U.S. patent application number 14/292328 was filed with the patent office on 2015-12-03 for systems and methods for monitoring castings.
The applicant listed for this patent is Elwha LLC. Invention is credited to William D. Duncan, Roderick A. Hyde, Jordin T. Kare, Lowell L. Wood, JR..
Application Number | 20150343530 14/292328 |
Document ID | / |
Family ID | 54700691 |
Filed Date | 2015-12-03 |
United States Patent
Application |
20150343530 |
Kind Code |
A1 |
Duncan; William D. ; et
al. |
December 3, 2015 |
SYSTEMS AND METHODS FOR MONITORING CASTINGS
Abstract
A control system for a casting process includes a sensor
positioned to monitor a property of a cast product during the
casting process and provide a corresponding sensing signal. The
control system also includes a processing circuit configured to
generate a real-time model of the cast product based on the
corresponding sensing signal and determine a control variable using
the real-time model of the cast product. The control variable
relates to a real-time modification of the cast product.
Inventors: |
Duncan; William D.; (Mill
Creek, WA) ; Hyde; Roderick A.; (Redmond, WA)
; Kare; Jordin T.; (Seattle, WA) ; Wood, JR.;
Lowell L.; (Bellevue, WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Elwha LLC |
Bellevue |
WA |
US |
|
|
Family ID: |
54700691 |
Appl. No.: |
14/292328 |
Filed: |
May 30, 2014 |
Current U.S.
Class: |
164/154.6 ;
164/154.1 |
Current CPC
Class: |
B22D 46/00 20130101;
B22D 2/00 20130101; B22D 11/16 20130101; B22D 2/006 20130101; B22D
2/008 20130101 |
International
Class: |
B22D 46/00 20060101
B22D046/00 |
Claims
1. A control system for a casting process, comprising: a sensor
positioned to monitor a property of a cast product during the
casting process and provide a corresponding sensing signal; and a
processing circuit configured to: generate a real-time model of the
cast product based on the corresponding sensing signal; and
determine a control variable using the real-time model of the cast
product, wherein the control variable relates to a real-time
modification of the cast product.
2-22. (canceled)
23. The system of claim 1, wherein the property of the cast product
includes at least one of a temperature, a flow, a stress, a strain,
a viscosity, a porosity, a phase boundary, a conductivity, a
current, and a magnetic field of the cast product.
24. The system of claim 1, wherein the control variable relates to
at least one of an applied surface heating, an applied surface
cooling, an applied volumetric heating, an applied surface force,
an applied volumetric force, an applied surface displacement, an
applied current, an applied magnetic field, and an applied
voltage.
25. The system of claim 1, wherein the processing circuit is
configured to determine the control variable by optimizing a
casting function relating to a condition of the cast product.
26. The system of claim 25, wherein the condition of the cast
product includes at least one of a phase, a phase distribution, a
porosity, a strength, a stress characteristic, a strain
characteristic, a fatigue characteristic, a creep characteristic, a
vibrational mode, a vibrational frequency, a ductility, a
stress-strain characteristic, and a uniformity of the cast
product.
27. The system of claim 25, wherein the condition of the cast
product includes at least one of an expense, a work input, a
heating input, and a cooling input required during the casting
process.
28. The system of claim 25, wherein the processing circuit is
configured to optimize the casting function while satisfying a
constraint function.
29. The system of claim 28, wherein the constraint function
includes a threshold value for the control variable.
30. The system of claim 28, wherein the constraint function
includes at least one of a time, a material usage, an expense, a
work input, a heating input, and a cooling input associated with
the casting process.
31. The system of claim 25, wherein the processing circuit is
configured to optimize the casting function by evaluating the
effect on the casting function of a first control strategy and a
second control strategy in real-time.
32. The system of claim 31, wherein the processing circuit is
configured to evaluate the first control strategy and the second
control strategy in parallel.
33. The system of claim 31, wherein the processing circuit is
configured to determine the first control strategy based on
differentiation of the casting function with respect to a first
control variable, and wherein the processing circuit is configured
to determine the second control strategy based on differentiation
of the casting function with respect to a second control
variable.
34. The system of claim 31, wherein the processing circuit is
configured to determine the first control strategy using a filter
relating a first control variable to the corresponding sensing
signal, and wherein the processing circuit is configured to
determine the second control strategy using the filter relating a
second control variable to the corresponding sensing signal.
35-50. (canceled)
51. A casting apparatus, comprising: a mold configured to receive
molten material as part of a casting process, wherein the mold
includes a sidewall that at least partially shapes a cast product;
a sensor positioned to monitor a property of the cast product
during the casting process and provide a corresponding sensing
signal; a processing circuit configured to: generate a real-time
model of the cast product based on the corresponding sensing
signal; and determine a control variable using the real-time model
of the cast product; and a regulation system configured to modify
the cast product during the casting process as a function of the
control variable.
52-67. (canceled)
68. The apparatus of claim 51, wherein the regulation system
includes an actuator coupled to the processing circuit and
configured to apply a force to the cast product during the casting
process, wherein the force varies based on the control
variable.
69. The apparatus of claim 68, wherein the force includes at least
one of a surface force and a volumetric force.
70. The apparatus of claim 68, wherein at least one of a magnitude,
a location, and a direction of the force varies based on the
control variable.
71. The apparatus of claim 51, wherein the regulation system
includes a thermal regulation system coupled to the processing
circuit and configured to vary the temperature of the cast product
during the casting process.
72. The apparatus of claim 71, wherein the thermal regulation
system includes a heater configured to provide at least one of
surface heating and volumetric heating to the cast product.
73. The apparatus of claim 71, wherein the thermal regulation
system includes an electrical device configured to resistively heat
at least one of a surface and a volume of the cast product.
74. The apparatus of claim 71, wherein the thermal regulation
system is configured to reduce the temperature of the cast
product.
75. The apparatus of claim 74, wherein the thermal regulation
system includes a spray nozzle configured to apply a coolant fluid
to an outer surface of the cast product.
76. The apparatus of claim 74, wherein the thermal regulation
system includes a conduit configured to transport a coolant fluid
in thermal contact an outer surface of the cast product.
77. The apparatus of claim 51, wherein the regulation system
includes an electrical device coupled to the processing circuit and
positioned to engage the cast product with an electrical
signal.
78. The apparatus of claim 77, wherein the electrical device is
configured to apply at least one of a current, an electric field,
and a voltage to the cast product.
79. The apparatus of claim 51, wherein the regulation system
includes a magnetic field generator coupled to the processing
circuit and positioned to apply a magnetic field to the cast
product, wherein the magnetic field varies based on the control
variable.
80-97. (canceled)
98. A casting apparatus, comprising: a mold configured to receive
molten material as part of a casting process, wherein the mold
includes a sidewall that at least partially shapes a cast product;
a first probe configured to engage the cast product with a test
signal and provide a sensing signal relating to a property of the
cast product; a processing circuit configured to: determine a
volumetric temperature profile of the cast product during the
casting process based on the sensing signal; and determine a
control variable using the volumetric temperature profile; and a
regulation system configured to modify the cast product during the
casting process as a function of the control variable.
99. The apparatus of claim 98, wherein the first probe includes an
ultrasound transducer and the test signal includes a plurality of
ultrasound waves, wherein interaction of the plurality of
ultrasound waves with the cast product produces a plurality of
response signals, and wherein the sensing signal is related to the
plurality of response signals.
100. The apparatus of claim 99, wherein the first probe is
configured to engage the cast product with the test signal by at
least one of transmitting the plurality of ultrasound waves and
receiving the plurality of response signals.
101-109. (canceled)
110. The apparatus of claim 98, wherein the first probe includes at
least one of an electrical signal generator and an electrical
signal receiver and the test signal includes an electrical signal,
wherein the sensing signal is related to an amount of current that
passes through the cast product.
111. The apparatus of claim 110, wherein the processing circuit is
configured to determine the volumetric temperature profile of the
cast product based on the thermal variation of electrical
conductivity.
112. The apparatus of claim 98, wherein the first probe includes at
least one of a magnetic field generator and a magnetic field sensor
and the test signal includes a magnetic field.
113. The apparatus of claim 112, wherein the processing circuit is
configured to determine the volumetric temperature profile of the
cast product based on the thermal variation of permeability.
114-116. (canceled)
117. The apparatus of claim 98, wherein the processing circuit is
configured to generate a real-time model of the cast product based
on the sensing signal, and wherein the processing circuit is
configured to determine the control variable using a
simulation-based control algorithm.
118. The apparatus of claim 98, wherein the processing circuit is
configured to determine the control variable using a parametric
control algorithm.
119-239. (canceled)
Description
BACKGROUND
[0001] Casting processes are used to produce various cast products.
Continuous casting processes may produce a semi-finished cast
product (e.g., an ingot, a billet, a bloom, a slab, etc.) that is
later subjected to secondary processing (e.g., cold-worked,
hot-worked, etc.) to produce a final shape. Batch casting (e.g.,
investment casting, die casting, sand casting, etc.) is used to
produce cast products that may not be subjected to secondary
processing.
[0002] Traditional casting processes involve pouring a molten
material into a mold and thereafter removing the cast product. The
shape of the mold and the use of auxiliary design features (e.g., a
sprue having a particular shape) are used to control one or more
properties of the cast product (e.g., porosity). Defects or other
deficiencies in the cast product are traditionally measured after
the cast product has solidified, thereby requiring additional
processing steps to produce a cast product that meets one or more
design specifications. In other casting processes, cast products
are iteratively produced until the design specifications are
satisfied (e.g., the shape or position of the sprue may be varied
between pours). Secondary processing or iterative production is
expensive, produces non-uniform cast products, and reduces the
efficiency of the casting process.
SUMMARY
[0003] One embodiment relates to a control system for a casting
process. The control system includes a sensor positioned to monitor
a property of a cast product during the casting process and provide
a corresponding sensing signal. The control system also includes a
processing circuit configured to generate a real-time model of the
cast product based on the corresponding sensing signal and
determine a control variable using the real-time model of the cast
product. The control variable relates to a real-time modification
of the cast product.
[0004] Another embodiment relates to a casting apparatus that
includes a mold, a sensor, a processing circuit, and a regulation
system. The mold is configured to receive molten material as part
of a casting process and includes a sidewall that at least
partially shapes a cast product. The sensor is positioned to
monitor a property of the cast product during the casting process
and provide a corresponding sensing signal. The processing circuit
is configured to generate a real-time model of the cast product
based on the corresponding sensing signal and determine a control
variable using the real-time model of the cast product. The
regulation system is configured to modify the cast product during
the casting process as a function of the control variable.
[0005] Still another embodiment relates to a casting apparatus that
includes a mold, an ultrasound transducer, a processing circuit,
and a regulation system. The mold is configured to receive molten
material as part of a casting process and includes a sidewall that
at least partially shapes a cast product. The ultrasound transducer
is positioned to engage the cast product with a plurality of
ultrasound waves, interaction of the plurality of ultrasound waves
with the cast product producing a plurality of response signals.
The processing circuit is configured to determine a volumetric flow
property of the cast product during the casting process by
evaluating a Doppler shift based on the plurality of response
signals and determine a control variable using the volumetric flow
property. The regulation system is configured to modify the cast
product during the casting process as a function of the control
variable.
[0006] Yet another embodiment relates to a casting apparatus that
includes a mold, a first probe, a processing circuit, and a
regulation system. The mold is configured to receive molten
material as part of a casting process and includes a sidewall that
at least partially shapes a cast product. The first probe is
configured to engage the cast product with a test signal and
provide a sensing signal relating to a property of the cast
product. The processing circuit is configured to determine a
volumetric temperature profile of the cast product during the
casting process based on the sensing signal and determine a control
variable using the volumetric temperature profile. The regulation
system is configured to modify the cast product during the casting
process as a function of the control variable.
[0007] Another embodiment relates to a method for actively
controlling a casting process. The method includes monitoring a
property of a cast product during the casting process using a
sensor, providing a corresponding sensing signal with the sensor,
generating a real-time model of the cast product based on the
corresponding sensing signal, and determining a control variable
using the real-time model of the cast product. The control variable
relates to a real-time modification of the cast product.
[0008] Another embodiment relates to a method for actively
controlling a casting process. The method includes providing a mold
configured to at least partially shape a cast product as part of a
casting process, monitoring a property of the cast product during
the casting process using a sensor, providing a corresponding
sensing signal with the sensor, generating a real-time model of the
cast product based on the corresponding sensing signal, determining
a control variable using the real-time model of the cast product,
and modifying the cast product during the casting process as a
function of the control variable.
[0009] Another embodiment relates to a method of manufacturing a
cast product. The method includes providing molten material to a
mold having a sidewall configured to at least partially shape a
cast product as part of a casting process, engaging the cast
product with a plurality of ultrasound waves using an ultrasound
transducer, interaction of the plurality of ultrasound waves with
the cast product producing a plurality of response signals,
determining a volumetric flow property of the cast product during
the casting process by evaluating a Doppler shift based on the
plurality of response signals with a processing circuit,
determining a control variable using the volumetric flow property,
and modifying the cast product during the casting process as a
function of the control variable with a regulation system.
[0010] Another embodiment relates to a method of manufacturing a
cast product. The method includes providing a molten material to a
mold having a sidewall configured to at least partially shape a
cast product as part of a casting process, engaging the cast
product with a test signal using a first probe configured to
provide a sensing signal relating to a property of the cast
product, determining a volumetric temperature profile of the cast
product during the casting process with a processing circuit based
on the sensing signal, determining a control variable using the
volumetric temperature profile, and modifying the cast product
during the casting process as a function of the control variable
with a regulation system.
[0011] The foregoing summary is illustrative only and is not
intended to be in any way limiting. In addition to the illustrative
aspects, embodiments, and features described above, further
aspects, embodiments, and features will become apparent by
reference to the drawings and the following detailed
description.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 is a schematic view of a continuous casting apparatus
including a mold, a sensor, and a regulation system, according to
one embodiment.
[0013] FIGS. 2-3 are detail views of the casting apparatus shown in
FIG. 1, according to one embodiment.
[0014] FIG. 4 is a graphical representation of a casting function
that relates to a condition of a cast product and is a function of
a control variable, according to one embodiment.
[0015] FIG. 5 is a schematic view of a regulation system including
an actuator, according to one embodiment.
[0016] FIG. 6 is a schematic view of a thermal regulation system,
according to one embodiment.
[0017] FIG. 7 is a schematic sectional view of a batch casting
apparatus including a mold, a sensor, and a regulation system,
according to one embodiment.
[0018] FIG. 8 is a schematic view of a continuous casting apparatus
including a mold, an ultrasound transducer, and a regulation
system, according to one embodiment.
[0019] FIG. 9 is a detail view of the casting apparatus shown in
FIG. 8, according to one embodiment.
[0020] FIG. 10 is a schematic view of a continuous casting
apparatus including a mold, a probe, and a regulation system,
according to one embodiment.
[0021] FIG. 11 is a detail view of the casting apparatus shown in
FIG. 10, according to one embodiment.
[0022] FIGS. 12-13 are schematic views of methods for controlling a
casting process, according to various embodiments.
DETAILED DESCRIPTION
[0023] In the following detailed description, reference is made to
the accompanying drawings, which form a part hereof. In the
drawings, similar symbols typically identify similar components,
unless context dictates otherwise. The illustrative embodiments
described in the detailed description, drawings, and claims are not
meant to be limiting. Other embodiments may be utilized, and other
changes may be made, without departing from the spirit or scope of
the subject matter presented here.
[0024] According to one embodiment, a casting process is actively
controlled to reduce the prevalence of defects within cast
products. In one embodiment, the casting process begins with
pouring molten material into a mold and continues until the molten
material solidifies (e.g., until all of the molten material
solidifies). In another embodiment, the casting process begins with
pouring molten material into a mold and continues until the cast
product cools to ambient temperature. A sensor monitors a property
of the cast product during the casting process, and a processing
circuit determines a control variable relating to a real-time
modification (i.e., an active modification, an intra-run
modification, a modification prior to complete solidification of
the cast product, etc.) of the cast product. A regulation system is
configured to modify the cast product during the casting process as
a function of the control variable.
[0025] Referring to the embodiment shown in FIGS. 1-2, a casting
apparatus, shown as continuous casting apparatus 10, is operated to
perform a casting process. According to one embodiment, the casting
process is a continuous casting process. As part of the continuous
casting process, a molten material (e.g., plastic, metal, etc.) is
shaped into a semi-finished cast product (e.g., an ingot, a billet,
a bloom, a slab, etc.) in a primary processing step. The
semi-finished cast product may be thereafter subjected to a
secondary processing step (e.g., hot-worked, cold-worked, etc.) and
shaped into a finished cast product. In other embodiments, the
molten material is shaped into a finished cast product. According
to the embodiment shown in FIGS. 1-2, molten material 20 is stored
within ladle 30. In one embodiment, ladle 30 includes main body 32
and spout 34. Molten material 20 is provided to tundish 40 through
spout 34, according to one embodiment. As shown in FIG. 1, tundish
40 includes main body 42 and shroud 44. According to one
embodiment, molten material 20 flows from main body 42 of tundish
40, through shroud 44, and into a mold, shown as mold 50. Stopper
46 may vary a flow characteristic (e.g., a flow rate) of molten
material 20 from tundish 40.
[0026] Mold 50 is configured to receive molten material as part of
the continuous casting process. According to the embodiment shown
in FIGS. 1-2, mold 50 includes a sidewall, shown as sidewall 52,
that at least partially shapes molten material 20 into a cast
product, shown as cast product 60. In one embodiment, mold 50
includes a plurality of plates having inner surfaces that define
sidewalls 52. The plurality of plates may be cooled (e.g., with
water) to facilitate at least partially shaping cast product
60.
[0027] As shown in FIG. 1, cast product 60 includes first end 62
having a vertical orientation and second end 64 having a horizontal
orientation. According to the embodiment shown in FIG. 1, a
plurality of guides, shown as rollers 70, facilitate the transition
of cast product 60 between the vertical and horizontal
orientations. In one embodiment, the portion of cast product 60
that transitions between first end 62 and second end 64 defines a
curved zone. According to another embodiment, cast product 60
includes first and second ends both having a vertical orientation,
both having a horizontal orientation (i.e., continuous casting
apparatus 10 may be a horizontal casting apparatus), or having
still another orientation.
[0028] Referring still to the embodiment shown in FIGS. 1-2,
continuous casting apparatus 10 includes sensor 80. Sensor 80 is
positioned to monitor a property of cast product 60 during the
continuous casting process. In one embodiment, the property of cast
product 60 includes at least one of a temperature, a flow, a
stress, a strain, a porosity, a viscosity, a phase boundary, a
conductivity, a current, and a magnetic field of cast product 60.
Sensor 80 may measure the property directly (e.g., sensor 80 may
include a strain gauge, sensor 80 may measure the current or flow,
etc.) or facilitate the indirect measurement of the property (e.g.,
sensor 80 may be configured to emit beams that scatter as a
function of porosity, etc.).
[0029] As shown in FIG. 1, sensor 80 is positioned to monitor
second end 64 of cast product 60. In other embodiments, sensor 80
is positioned along the curved zone of cast product 60 or
positioned to monitor first end 62 of cast product 60. As shown in
FIG. 2, sensor 80 may be positioned to monitor cast product 60 as
it exits mold 50 or positioned to monitor cast product 60 within
mold 50. By way of example, sensor 80 may be coupled to sidewall 52
of mold 50. Sensor 80 may be disposed along an inner surface of
sidewall 52 such that sensor 80 engages an outer surface of cast
product 60. In another embodiment, sensor 80 protrudes into an
inner volume of mold 50 such that sensor 80 engages an inner volume
of cast product 60. Such a sensor 80 may facilitate intensive
measurement of cast product 60. By way of example sensor 80 may
include a thermocouple. In other embodiments, sensor 80 is disposed
entirely within an inner volume of mold 50. In still other
embodiments, sensor 80 is positioned along an outer surface of mold
50 or within an inner volume of sidewall 52. Continuous casting
apparatus 10 may include a plurality of sensors 80 positioned to
monitor a single property at various locations of cast product 60,
a plurality of properties at a single location of cast product 60,
or a plurality of properties at various locations of cast product
60.
[0030] In one embodiment, sensor 80 is configured to monitor the
property at an inner volume of cast product 60. In another
embodiment, sensor 80 is configured to monitor the property at an
outer surface of cast product 60. Sensor 80 may be positioned at
least partially within the inner volume of cast product 60,
positioned along an outer surface of cast product 60, or spaced
from cast product 60. In one embodiment, sensor 80 protrudes into
the inner volume through an outer surface of cast product 60. By
way of example, sensor 80 may include a thermocouple. By way of
another example, sensor 80 may include at least one of a strain
gauge, a flow meter, a force gauge, a viscometer, an ultrasound
transducer, an x-ray detector, a resistor, a current meter, and a
magnetometer. In another embodiment, sensor 80 includes a
transmitter configured to wirelessly convey the corresponding
sensing signal from within cast product 60. In still another
embodiment, sensor 80 is spaced from cast product 60 and configured
to remotely monitor the property of cast product 60. By way of
example, sensor 80 may include a pyrometer. By way of another
example, sensor 80 may include at least one of a thermal imager, an
ultrasound transducer, an x-ray detector, a microscope, and a
magnetometer.
[0031] According to one embodiment, the property monitored by
sensor 80 includes a temperature of cast product 60. By way of
example, sensor 80 may be positioned to monitor a temperature at an
outer surface of cast product 60. By way of another example, sensor
80 may be positioned to monitor a temperature within cast product
60. According to another embodiment, sensor 80 is positioned to
monitor a flow of material (e.g., molten material) within cast
product 60. According to still other embodiments, sensor 80 is
positioned to monitor at least one of a stress (e.g., a stress
within the material of cast product 60), a strain (e.g., a strain
within the material of cast product 60), a porosity of cast product
60, a phase boundary (e.g., a boundary between molten and solid
material, a boundary between two or more constituents of cast
product 60, etc.) within cast product 60, a conductivity of cast
product 60, a current flow through cast product 60, and interaction
of a magnetic field with cast product 60.
[0032] In one embodiment, sensor 80 monitors the property of cast
product 60 and provides a corresponding sensing signal. The
corresponding sensing signal may relate to the property of cast
product 60. By way of example, sensor 80 may be configured to
monitor the temperature of cast product 60, and the corresponding
sensing signal may have a voltage that varies based on the measured
temperature of cast product 60.
[0033] Referring still to the embodiment shown in FIG. 1,
continuous casting apparatus 10 includes regulation system 90
configured to modify cast product 60 (e.g., change a property of
cast product 60, physically alter cast product 60, etc.) during the
casting process. Regulation system 90 reduces the prevalence of
defects within cast product 60 (e.g., irregular grain boundaries,
porosity, overall dimensional shape, etc.), according to one
embodiment. Regulation system 90 modifies cast product 60 during
the casting process, thereby reducing or eliminating the portions
of cast product 60 that contain defects prior to completion of the
continuous casting process. In one embodiment, regulation system 90
reduces the portion of cast product 60 having properties below a
threshold value (e.g., tensile strength below a published value,
porosity above a maximum value, etc.). Accordingly, regulation
system 90 reduces the need to subsequently rework cast product 60
(e.g., reduces the need to rework certain portions of cast product
60, reduces the level of rework required, etc.), thereby reducing
the overall production costs.
[0034] In one embodiment, regulation system 90 is configured to
apply a force to cast product 60 during the casting process. In
another embodiment, regulation system 90 is configured to vary the
temperature of at least a portion of cast product 60 (e.g., apply
heat to cast product 60, apply water or another cooling fluid to
cast product 60, etc.). In still another embodiment, regulation
system 90 is configured to engage cast product 60 with an electric
signal (e.g., a current, an electric field, etc.). In yet another
embodiment, regulation system 90 is configured to apply a magnetic
field to cast product 60.
[0035] Referring still to FIG. 1, molten material 20 is initially
stored within ladle 30. In one embodiment, molten material 20 is
poured into ladle 30 from a furnace. As molten material 20 flows
into mold 50, portions thereof begin to solidify through
nucleation. Portions of molten material 20 having a lower
temperature (e.g., a temperature below the freezing temperature)
begin to solidify before portions of molten material 20 having a
higher temperature (e.g., a temperature above the freezing
temperature). In one embodiment, the outer portions of cast product
60 begin to solidify before the inner portions of cast product 60.
By way of example, cast product 60 may have an outer layer of
solidified material (e.g., a layer in contact with sidewalls 52 of
mold 50) and an inner volume of molten material 20 at first end 62.
The entire volume of cast product 60 may be solidified at second
end 64.
[0036] Upon initial solidification, molten material 20 may
transition into various solid phases. The solid phases that are
formed may be related to the composition of molten material 20. In
one embodiment, molten material 20 is steel and includes a mixture
of iron and carbon. Molten material 20 may initially solidify into
6-ferrite or austenite. The solid phase that is formed may vary
based upon the composition of molten material 20. In one
embodiment, molten material 20 is a hypoeutectic steel that
includes iron and 0.75 weight percent carbon, and austenite is
initially formed during solidification. Further reduction in the
temperature may result in the formation of ferrite and cementite.
The strength, ductility, or other characteristics of cast product
60 may be impacted by the solid phases formed therein. According to
one embodiment, regulation system 90 is configured to vary the
solid phases within cast product 60 by controlling the eutectoid
reaction (e.g., regulation system 90 dispersion strengthens the
alloy). By way of example, regulation system 90 may introduce an
agent (e.g., carbon) to cast product 60 to change the composition
of the alloy and increase the amount of cementite therein (e.g., to
increase the carbon content of the steel). By way of another
example, regulation system 90 may be a burner and reduce the grain
size by controlling the temperature of cast product 60. By way of
still another example, regulation system 90 may include a spray
nozzle configured to apply a cooling fluid, thereby increasing the
cooling rate during the eutectoid reaction and increasing the
strength of the alloy. By way of yet another example, regulation
system 90 may lower the transformation temperature at which the
eutectoid reaction begins.
[0037] Referring next to FIG. 3, a partial block diagram of
continuous casting apparatus 10 is shown, according to one
embodiment. Continuous casting apparatus 10 may be configured to
actively modify cast product 60 during a continuous casting process
using a real-time model of cast product 60. As shown in FIG. 3,
continuous casting apparatus 10 includes processing circuit 100.
Processing circuit 100 may be implemented as a general-purpose
processor, an application specific integrated circuit (ASIC), one
or more field programmable gate arrays (FPGAs), a
digital-signal-processor (DSP), circuits containing one or more
processing components, circuitry for supporting a microprocessor, a
group of processing components, or other suitable electronic
processing components.
[0038] According to the embodiment shown in FIG. 3, processing
circuit 100 includes processor 102 and memory 104. Processor 102
may include an ASIC, one or more FPGAs, a DSP, circuits containing
one or more processing components, circuitry for supporting a
microprocessor, a group of processing components, or other suitable
electronic processing components. In some embodiments, processor
102 is configured to execute computer code stored in memory 104 to
facilitate the activities described herein. Memory 104 may be any
volatile or non-volatile computer-readable storage medium capable
of storing data or computer code relating to the activities
described herein. In one embodiment, memory 104 has computer code
modules (e.g., executable code, object code, source code, script
code, machine code, etc.) configured for execution by processor
102. In some embodiments, processing circuit 100 represents a
collection of processing devices (e.g., servers, data centers,
etc.). In such cases, processor 102 represents the collective
processors of the devices, and memory 104 represents the collective
storage devices of the devices.
[0039] According to one embodiment, processing circuit 100 is
coupled to sensor 80 and regulation system 90. Processing circuit
100 is configured to evaluate the corresponding sensing signal
provided by sensor 80 and generate a real-time model of cast
product 60 based on the corresponding sensing signal, according to
one embodiment. Processing circuit 100 may determine a control
variable using the real-time model of cast product 60. In one
embodiment, processing circuit 100 utilizes a physics simulator or
another numerical simulator to generate the real-time model. The
control variable is related to a real-time modification of the cast
product. In one embodiment, regulation system 90 is configured to
modify cast product 60 during the casting process as a function of
the control variable. In one embodiment, a control system for a
casting process includes sensor 80 and processing circuit 100.
[0040] Referring still to the embodiment shown in FIG. 3,
processing circuit 100 is configured to generate the real-time
model of cast product 60 based on the corresponding sensing signal
provided by sensor 80. In one embodiment, processing circuit 100
generates the real-time model during the continuous casting process
(e.g., before termination of the pour). The real-time model may
include a computer-based representation of cast product 60. By way
of example, the real-time model may include a plurality of discrete
computational nodes that form at least part of a computer-based
mesh representing cast product 60. By way of another example, the
real-time model may include a plurality of discrete unit volumes
that form at least part of a computer-based model representing cast
product 60.
[0041] According to one embodiment, the real-time model of cast
product 60 is based on a parameter (e.g., the material of cast
product 60, the heat transfer coefficient of the material of cast
product 60, the relationship of conductivity or permeability as a
function of temperature for the material of cast product 60, etc.).
In one embodiment, processing circuit 100 is configured to derive
the parameter empirically using the corresponding sensing signal.
In other embodiments, processing circuit 100 is configured to
calculate the parameter using numerical simulation. In still other
embodiments, the parameter is stored within a memory (e.g.,
pre-programmed, etc.) or provided by an operator via a
user-interface.
[0042] In one embodiment, processing circuit 100 updates the
real-time model during the continuous casting process. By way of
example, processing circuit 100 may update the real-time model
during an elapsed time between the beginning and termination of the
pour. Processing circuit 100 may update the real-time model
according to a refresh rate. Such an update may include calculating
or otherwise simulating one or more values for at least one of the
discrete computational nodes or unit volumes. In one embodiment,
the refresh rate is related to (e.g., equal to) a sensing rate at
which sensor 80 monitors the property of cast product 60. In
another embodiment, the refresh rate is a multiple of the sensing
rate (e.g., a refresh rate of half the sensing rate).
[0043] Processing circuit 100 may be configured to generate the
real-time model using computer simulation (e.g., numerical
simulation, etc.). In one embodiment, processing circuit 100 is
configured to perform numerical simulation in real-time (e.g.,
continuously, according to a refresh rate, etc.). In other
embodiments, processing circuit 100 is configured to perform the
numerical simulation asynchronously. According to one embodiment,
the numerical simulation includes determining at least one of a
phase transition within cast product 60, a thermal transport within
cast product 60, a porosity of at least a region of cast product
60, a chemical reaction within cast product 60, a precipitation of
the material of cast product 60, and a segregation within cast
product 60. By way of example, the phase transition may include at
least one of a molten-molten phase transition, a molten-solidified
phase transition (i.e., the region between the molten and
solidified material of cast product 60), and a solid-solid phase
transition (i.e., a transition between different solid-phase
regions).
[0044] According to another embodiment, the numerical simulation
includes determining at least one of a stress, a strain, a
viscosity, a flow, a pressure, a shear force, a body force, an
induction, and a current transport within cast product 60. By way
of example, the body force may include at least one of a force due
to gravity and a Lorentz force acting on a unit volume of cast
product 60. By way of another example, a pressure within cast
product 60 may occur due to the flow of molten material 20. Such
flow may generate a ferrostatic pressure of the solidifying molten
material 20 against the solid outer walls of cast product 60.
[0045] According to one embodiment, the numerical simulation
includes at least one of a space dependence, a time dependence, and
a boundary condition dependence of cast product 60. The space
dependence may include computing or otherwise simulating one or
more values for different portions of cast product 60 (e.g.,
different locations along a cross-sectional plane of cast product
60, different locations along the length of cast product 60,
different locations within the entire cast product 60, etc.). The
time dependence may include computing or otherwise simulating
different values for different elapsed times (e.g., measured from
the beginning of the pour). Such different values may be computed
independently, or later values may be computed using
previously-determined values for a particular node or unit volume.
In one embodiment, the boundary condition includes at least one of
a stress, a heating rate, a cooling rate, and a temperature at a
surface of the cast product.
[0046] According to the embodiment shown in FIG. 3, processing
circuit 100 is configured to determine the control variable using
the real-time model of cast product 60. In one embodiment, the
control variable relates to at least one of an applied surface
heating, an applied surface cooling, an applied surface force, an
applied volumetric force, an applied surface displacement, an
applied current, an applied magnetic field, and an applied voltage.
By way of example, the control variable may include a selection of
a real-time modification of cast product 60 (e.g., whether to apply
heat or apply a force). By way of another example, the control
variable may include a signal relating to a magnitude or actuation
profile for regulation system 90.
[0047] Referring next to FIG. 4, processing circuit 100 is
configured to determine the control variable by optimizing a
casting function, shown as casting function 110. As shown in FIG.
4, casting function 110 is related to a condition of the cast
product and is a function of the control variable. By way of
example, the condition may include at least one of a phase, a phase
distribution, a porosity, a strength, a stress characteristic, a
strain characteristic, a fatigue characteristic, a creep
characteristic, a vibrational mode, a vibrational frequency, a
ductility, a stress-strain characteristic, and a uniformity of a
cast product. By way of another example, the condition may include
at least one of an expense, a work input, a heating input, and a
cooling input required during the casting process. The condition
may be determined using the real-time model of the cast product. By
way of example, the condition may be a current condition or a
projected future condition, either of which may be calculated based
on, or as part of, the real-time model of the cast product.
According to one embodiment, casting function 110 provides a
fatigue characteristic (e.g., toughness) as a function of the
control variable. By way of example, the fatigue characteristic may
be a function of the amount of thermal energy removed or applied to
a surface of the cast product.
[0048] According to one embodiment, processing circuit 100 is
configured to differentiate casting function 110 with respect to
the control variable. Such differentiation may be used to determine
maxima (e.g., a local maximum, a global maximum, etc.) or minima of
casting function 110. As shown in FIG. 4, casting function 110
includes one maximum, shown as maximum 112. In one embodiment,
processing circuit 100 is configured to determine the control
variable (e.g., the amount of heat to apply to the cast product)
based on the control variable associated with maximum 112. In other
embodiments, processing circuit 100 is configured to determine the
control variable based on target condition 114 of the cast product.
Target condition 114 may be determined by evaluating the real-time
model of the cast product. By way of example, target condition 114
may be achieved by applying a first control variable 116 (e.g., a
first amount of thermal energy) or a second control variable 118
(e.g., a second amount of thermal energy). According to another
embodiment, processing circuit 100 is configured to differentiate
casting function 110 with respect to another variable. According to
still another embodiment, processing circuit 100 is configured to
determine the control variable by integrating casting function 110.
According to yet another alternative embodiment, processing circuit
100 is configured to optimize (e.g., differentiate, integrate,
utilize, etc.) still another casting function (e.g., a casting
function that relates to other variables).
[0049] In one embodiment, processing circuit 100 is configured to
optimize casting function 110 while satisfying a constraint
function. The constraint function may establish a threshold value
for the control value (e.g., a minimum, a maximum, etc.), may
facilitate selection between multiple solutions to casting function
110, or may facilitate selection between solutions for different
casting functions. By way of example, the constraint function may
include at least one of a time, a material usage, an expense, a
work input, a heating input, and a cooling input associated with
the casting process. In one embodiment, processing circuit 100 is
configured to optimize two or more casting functions to generate
two or more optimized solutions, and the constraint function is
configured to facilitate evaluation of, or selection between, the
two or more optimized solutions.
[0050] According to another embodiment, casting function 110 is a
function of a plurality of variables. In one embodiment, processing
circuit 100 is configured to optimize casting function 110 by
evaluating the effect on casting function 110 of executing a first
control strategy and a second control strategy. By way of example,
the first control strategy and the second control strategy may
include approaches for determining an appropriate control variable
for use by a regulation system. The approaches may include
procedures for evaluating or otherwise manipulating casting
function 110 (e.g., differentiate casting function 110, integrate
casting function 110, select the smallest solution to casting
function 110 for a particular condition, etc.). Processing circuit
100 simulates execution of the control strategies to facilitate
determining the control variable, according to one embodiment.
Processing circuit 100 may optimize casting function 110 in
real-time or asynchronously. In one embodiment, processing circuit
100 is configured to determine the first control strategy by
differentiating casting function 110 with respect to a first
variable and determine the second control strategy based by
differentiating casting function 110 with respect to a second
variable. By way of example, casting function 110 may relate the
fatigue strength of a cast product to a temperature of an applied
cooling fluid and a flow rate of the applied cooling fluid. The
first control strategy may relate the fatigue strength of the cast
product to the temperature of the applied cooling fluid, and the
second control strategy may relate the fatigue strength of the cast
product to the flow rate of the applied cooling fluid. In one
embodiment, processing circuit 100 is configured to optimize
casting function 110 by differentiating casting function 110 with
respect to the temperature of the applied cooling fluid and with
respect to the flow rate of the applied cooling fluid. In still
other embodiments, processing circuit 100 is configured to
otherwise manipulate casting function 110 (e.g., integrate,
evaluate, etc.) to determine the first control strategy and the
second control strategy. According to one embodiment, processing
circuit 100 evaluates the first control strategy and the second
control strategy in parallel. According to another embodiment,
processing circuit 100 sequentially evaluates the first control
strategy and the second control strategy.
[0051] According to another embodiment, casting function 110 is
related to the corresponding sensing signal provided by sensor 80.
By way of example, casting function 110 may be related to a
condition of a cast product and a function of the corresponding
sensing signal. According to another embodiment, casting function
110 is related to a condition of a cast product and a function of
both one or more sensing signals and one or more control variables.
According to still another embodiment, processing circuit 100 is
configured to determine a control strategy relating one or more
control variables to the one or more sensing signals. Processing
circuit 100 may be configured to determine the control strategy
using a filter relating the casting process, one or more control
variables, and the one or more sensing signals. The filter may
include a linear filter or a nonlinear filter. In one embodiment,
the filter includes a Kalman filter that refines (e.g., takes into
account signal noise, etc.) the sensing signals provided by sensor
80. According to another embodiment, processing circuit 100 is
configured to optimize casting function 110 based on a filter
relating one or more control variables to one or more sensing
signals (e.g., based on a filter relating the casting process, a
control variable, and a sensing signal, etc.). In one embodiment,
processing circuit 100 evaluates a first control strategy and the
second control strategy in parallel. In another embodiment,
processing circuit 100 sequentially evaluates a first control
strategy and the second control strategy.
[0052] According to one embodiment, processing circuit 100 is
configured to determine the control variable as casting function
110 exceeds a threshold value or a threshold gradient (e.g., as the
rate at which the fatigue strength is increasing exceeds a
threshold). According to another embodiment, processing circuit 100
is configured to determine the control variable by evaluating
casting function 110 until an end time (e.g., of the casting
process, of the simulation, etc.) is reached. According to still
another embodiment, processing circuit 100 is configured to
determine the control variable by evaluating casting function 110
until an event occurs. In one embodiment, the event is defined to
occur when casting function 110 exceeds a threshold value. In
another embodiment, the event is defined to occur when a property
of the cast product exceeds a threshold value.
[0053] According to another embodiment, processing circuit 100 is
configured to determine the control variable by optimizing a
condition of the cast product. By way of example, the condition of
the cast product may include a phase, a phase distribution, a
porosity, a strength, a stress characteristic, a strain
characteristic, a fatigue characteristic, a creep characteristic, a
vibrational mode, a vibrational frequency, a ductility, a
stress-strain characteristic, and a uniformity of the cast product.
By way of another example, the condition of the cast product may
include at least one of an expense, a work input, a heating input,
and a cooling input required during the casting process. In one
embodiment, processing circuit 100 is configured to optimize a
condition of the cast product while satisfying a constraint
function. By way of example, processing circuit 100 may use the
real-time model of the cast product to determine a condition of the
cast product and iteratively modify the control variable until a
constraint function is satisfied (e.g., until the porosity of the
cast product is below a threshold value).
[0054] Referring next to FIGS. 5-6, regulation system 90 is
configured to modify cast product 60 as a function of the control
variable. In one embodiment, regulation system 90 is configured to
vary an input condition (e.g., a temperature of the molten material
provided to the mold, a flow rate of the molten material provided
to the mold, a mold temperature, etc.) such that the continuous
casting process operates according to a closed-loop control
strategy. As shown in FIG. 5, regulation system 90 includes an
actuator, shown as roller 92, that is configured to apply a force
to cast product 60 during the casting process. According to another
embodiment, the actuator is another type of device (e.g., linear
actuator, etc.). The force applied to cast product 60 may vary
based on the control variable. By way of example, the control
variable may include information relating to a magnitude, a
location, and a direction of the force. According to the embodiment
shown in FIG. 5, roller 92 is moveable along a guide, shown as
track 94. An actuator may move roller 92 along track 94. Extension
of the actuator may move roller 92 toward cast product 60, thereby
increasing the magnitude of the applied force. The actuator may be
coupled to a processing circuit and move roller 92 as a function of
a control variable. Roller 92 includes a surface that engages an
outer surface of cast product 60, according to one embodiment. As
shown in FIG. 5, roller 92 is configured to apply a surface force
to cast product 60 during the casting process. In other
embodiments, the actuator is configured to apply a volumetric force
to cast product 60.
[0055] In one embodiment, the real-time model generated by the
processing circuit may indicate that cast product 60 has one or
more defects at a particular location. Regulation system 90 may
modify cast product 60 during the casting process as a function of
the control variable determined by processing circuit 100. In one
embodiment, sensor 80 is positioned to monitor the temperature of
cast product 60, and processing circuit 100 is configured to
generate the real-time model based on the corresponding sensing
signal. Processing circuit 100 may use the real-time model to
determine a control value relating a particular force to a
particular location of cast product 60. Regulation system 90 may
thereafter apply the force to cast product 60 at the particular
location, thereby reducing the prevalence of the defect without
subjecting the entire cast product 60 to the modification. Use of
the real-time model facilitates evaluation of various properties of
cast product 60 based on a single monitored property. Use of the
real-time model also facilitates monitoring and actively modifying
of cast product 60.
[0056] Referring now to FIG. 6, regulation system 90 includes a
thermal regulation system configured to vary the temperature of
cast product 60 during the casting process. In one embodiment, the
thermal regulation system is coupled to processing circuit 100 and
is configured to vary the temperature of cast product 60 as a
function of a control variable. According to the embodiment shown
in FIG. 6, the thermal regulation system includes a heater, shown
as burner 96. Burner 96 is configured to apply surface heating to
cast product 60. In another embodiment, the thermal regulation
system is configured to provide volumetric heating to cast product
60. According to another embodiment, the thermal regulation system
includes an electrical device configured to resistively heat at
least one of a surface and a volume of cast product 60 (e.g., with
an applied current, with applied microwaves, etc.). According to
still another embodiment, the thermal regulation system is
configured to reduce the temperature of cast product 60. By way of
example, the thermal regulation system may include a spray nozzle
configured to apply a coolant fluid (e.g., a vaporizable liquid, a
heatable gas, a heatable liquid, etc.) to an outer surface of cast
product 60. In one embodiment, the thermal regulation system
includes a conduit configured to transport a coolant fluid into
thermal contact with cast product 60. Such a conduit may, for
example, contact the outer surface of cast product 60, or may
extend within an interior volume of cast product 60.
[0057] According to one embodiment, the thermal regulation system
selectively heats cast product 60. The thermal regulation system
may selectively heat an outer surface of cast product 60 to a case
depth. In one embodiment, the thermal regulation system heats and
subsequently cools a portion of cast product 60. By way of example,
the thermal regulation system may heat and quench a portion of a
steel cast product 60. The case depth may include a layer of
martensite that is formed after quenching the heated portion of
cast product 60. In other embodiments, the thermal regulation
system applies heat and an agent as part of a diffusion processes
configured to vary a property of cast product 60. By way of
example, the thermal regulation system may heat and apply carbon,
liquid cyanide, nitrogen, or another agent, which diffuses into the
outer portion of cast product 60. Such a process may increase at
least one of the strength, hardness, and toughness of a portion of
cast product 60.
[0058] According to another embodiment, regulation system 90
includes an electrical device. In one embodiment, the electrical
device is coupled to processing circuit 100 and positioned to
engage cast product 60 with an electrical signal. The electrical
signal may vary based on a control variable determined by
processing circuit 100. In one embodiment, the electrical device is
configured to apply at least one of a current, an electric field,
and a voltage to cast product 60. By way of example, an electric
current or an electric field may facilitate volumetric heating of
cast product 60. The volumetric heating may occur during the
casting process and may be targeted to a particular portion of cast
product 60 (e.g., a portion of cast product 60 having a defect as
determined by processing circuit 100 evaluating one or more sensing
signals).
[0059] According to yet another embodiment, regulation system 90
includes a magnetic field generator. In one embodiment, the
magnetic field generator is coupled to processing circuit 100 and
positioned to apply a magnetic field to cast product 60. The
magnetic field may vary based on a control variable determined by
processing circuit 100. By way of example, the strength or
direction of the magnetic field may vary as a function of the
control variable. In one embodiment, the application of a magnetic
field generates a Lorentz force within cast product 60. Such a
Lorentz force may facilitate the application of volumetric forces
to cast product 60. The Lorentz force may be applied during the
casting process and may be targeted to a particular portion of cast
product 60 (e.g., a portion of cast product 60 having a defect as
determined by processing circuit 100 evaluating one or more sensing
signals).
[0060] Referring next to the embodiment shown in FIG. 7, a casting
apparatus, shown as batch casting apparatus 200, includes a mold,
shown as mold 210. According to one embodiment, a ladle, shown as
ladle 220, is configured to provide molten material 230 into mold
210 to produce a cast product as part of a batch casting process.
According to the embodiment shown in FIG. 7, mold 210 includes
sidewall 212 that defines an inner volume configured to at least
partially shape the cast product.
[0061] According to the embodiment shown in FIG. 7, batch casting
apparatus 200 includes sensor 240 configured to monitor a property
of the cast product during the batch casting process and provide a
corresponding sensing signal. In one embodiment, a processing
circuit is configured to evaluate the corresponding sensing signal,
generate a real-time model of the cast product based on the
corresponding sensing signal, and determine a control variable
using the real-time model of the cast product. The control variable
may relate to a real-time modification of the cast product.
[0062] As shown in FIG. 7, batch casting apparatus 200 includes
regulation system 250. In one embodiment, regulation system 250 is
configured to apply a force to the cast product (e.g., to molten
material 230, to a solidified portion of the cast product, etc.)
during the casting process. In another embodiment, regulation
system 250 is configured to vary the temperature of at least a
portion of the cast product (e.g., apply heat to the cast product,
apply water or another cooling fluid to the cast product, etc.). In
still another embodiment, regulation system 250 is configured to
engage the cast product with an electric signal. In yet another
embodiment, regulation system 250 is configured to apply a magnetic
field to the cast product. By way of example, regulation system 250
may include at least one of thermal regulation system (e.g., a
spray nozzle, a burner, etc.), an electrical device, and a magnetic
field generator.
[0063] Referring still to FIG. 7, sensor 240 is integrated into
mold 210. In one embodiment, sensor 240 is coupled to sidewall 212.
According to the embodiment shown in FIG. 7, sensor 240 is disposed
along an inner surface of sidewall 212 such that sensor 240 engages
an outer surface of the cast product. According to another
embodiment, sensor 240 protrudes into the inner volume of mold 210
such that sensor 240 engages an inner volume of the cast product.
By way of example, sensor 240 may include a thermocouple. In
another embodiment, sensor 240 includes a transmitter configured to
wirelessly convey the corresponding sensing signal from within the
cast product. According to another embodiment, sensor 240 is
otherwise positioned.
[0064] Referring next to the embodiment shown in FIG. 8, a casting
apparatus, shown as continuous casting apparatus 300, includes a
mold, shown as mold 310, that is configured to receive molten
material 320 as part of a continuous casting process. In another
embodiment, the casting apparatus includes a batch casting
apparatus that includes a mold configured to receive molten
material as part of a batch casting process. As shown in FIG. 8,
molten material 320 flows from tundish 330 into mold 310. In one
embodiment, mold 310 includes a sidewall, shown as sidewall 312,
that at least partially shapes a cast product, shown as cast
product 340. As shown in FIG. 8, cast product 340 includes first
end 342 having a vertical orientation and second end 344 having a
horizontal orientation. A plurality of guides, shown as rollers
350, facilitates the transition of cast product 340 between the
vertical and horizontal orientations. According to the embodiment
shown in FIG. 8, continuous casting apparatus 300 includes
ultrasound transducer 360. A coupling fluid (e.g., a gel, etc.) may
be applied to a surface of cast product 340 to facilitate imaging
with ultrasound transducer 360.
[0065] As shown in the detail view of FIG. 9, ultrasound transducer
360 is positioned to engage cast product 340 with a plurality of
ultrasound waves 362. In one embodiment, interaction of ultrasound
waves 362 with cast product 340 produces a plurality of response
signals 364. In one embodiment, transducer 360 both transmits
ultrasound waves 362 and receives (e.g., reflected, etc.) response
signals 364. In another embodiment, transducer 360 operates in
conjunction with a second ultrasound transducer. By way of example,
transducer 360 may transmit ultrasound waves 362 and the second
transducer may receive response signals 364. By way of another
example, the second transducer may transmit ultrasound waves 362
and the transducer 360 may receive response signals 364. In one
embodiment, response signals 364 are different than ultrasound
waves 362. By way of example, response signals 364 may have a
different amplitude, direction, frequency, or time delay than
ultrasound waves 362. Response signals 364 may have properties that
vary based on the characteristics of cast product 340 at the
location engaged by ultrasound waves 362 (e.g., a defective portion
of cast product 340 scatters ultrasound waves 362 differently than
a defect-free portion of cast product 340, the frequency dependence
of the scattering of ultrasound waves 362 may vary based on the
size distribution of phase boundaries in cast product 340, etc.).
According to one embodiment, an additive is mixed within molten
material 320 (e.g., prior to heating the material, after the
material becomes molten, etc.). The additive may be configured to
increase an ultrasonic contrast within cast product 340. By way of
example, the additive may include air bubbles, gas-filled micro
bubbles, or still another agent.
[0066] Referring again to FIG. 9, processing circuit 370 is coupled
to ultrasound transducer 360. Processing circuit 370 may be
implemented as a general-purpose processor, an application specific
integrated circuit (ASIC), one or more field programmable gate
arrays (FPGAs), a digital-signal-processor (DSP), circuits
containing one or more processing components, circuitry for
supporting a microprocessor, a group of processing components, or
other suitable electronic processing components. According to the
embodiment shown in FIG. 9, processing circuit 370 includes
processor 372 and memory 374. Processor 372 may include an ASIC,
one or more FPGAs, a DSP, circuits containing one or more
processing components, circuitry for supporting a microprocessor, a
group of processing components, or other suitable electronic
processing components. In some embodiments, processor 372 is
configured to execute computer code stored in memory 374 to
facilitate the activities described herein. Memory 374 may be any
volatile or non-volatile computer-readable storage medium capable
of storing data or computer code relating to the activities
described herein. In one embodiment, memory 374 has computer code
modules (e.g., executable code, object code, source code, script
code, machine code, etc.) configured for execution by processor
372. In some embodiments, processing circuit 370 represents a
collection of processing devices (e.g., servers, data centers,
etc.). In such cases, processor 372 represents the collective
processors of the devices, and memory 374 represents the collective
storage devices of the devices.
[0067] According to one embodiment, processing circuit 370 is
configured to determine a volumetric flow property of cast product
340 during the casting process. In one embodiment, the volumetric
flow property includes at least one of a speed, a direction, a
voracity, and a turbulence of the material within cast product 340.
The volumetric flow property may provide information regarding a
heat flow within cast product 340. Processing circuit 370 may
determine the volumetric flow property by evaluating a Doppler
shift based on response signals 364. By way of example, the Doppler
shift may include the difference in frequency between ultrasound
waves 362 and response signals 364, the difference in frequency
between various response signals 364, or still another variation.
In one embodiment, processing circuit 370 is configured to
determine a control variable using the volumetric flow
property.
[0068] According to one embodiment, processing circuit 370 is
configured to determine the volumetric flow property at a point
within cast product 340. According to another embodiment,
processing circuit 370 is configured to determine the volumetric
flow property for at least two points along a line within cast
product 340. According to still another embodiment, processing
circuit 370 is configured to determine the volumetric flow property
for a plurality of points along a plane within cast product 340.
According to still another embodiment, processing circuit 370 is
configured to determine the volumetric flow property on a surface
of cast product 340.
[0069] Processing circuit 370 may determine the volumetric flow
property for a particular location within cast product 340. In
another embodiment, processing circuit 370 is configured to
determine a cumulative volumetric flow property for cast product
340. By way of example, processing circuit 370 may be configured to
determine the cumulative volumetric flow property using a plurality
of points along a surface of cast product 340. By way of another
example, processing circuit 370 may be configured to determine the
cumulative volumetric flow property using a plurality of points
within an interior region of cast product 340.
[0070] In one embodiment, processing circuit 370 is configured to
determine the control variable using a simulation-based control
algorithm. Processing circuit 370 may be configured to generate a
real-time model of cast product 340 based on response signals 364,
and processing circuit 370 may be configured to determine the
control variable using a parametric control algorithm, according to
various embodiments. In another embodiment, processing circuit 370
includes a filter configured to relate a condition of cast product
340 to response signals 364. In one embodiment, the condition
includes at least one of a phase, a phase distribution, a porosity,
a strength, a stress characteristic, a strain characteristic, a
fatigue characteristic, a creep characteristic, a vibrational mode,
a vibrational frequency, a ductility, a stress-strain
characteristic, and a uniformity of cast product 340. In one
embodiment, the condition includes at least one of an expense, a
work input, a heating input, and a cooling input required during
the casting process.
[0071] As shown in FIGS. 8-9, continuous casting apparatus 300
includes regulation system 380. In one embodiment, regulation
system 380 is configured to modify cast product 340 during the
casting process as a function of the control variable. Regulation
system 380 may include an actuator, a thermal regulation system, an
electrical device, a magnetic field generator, or still another
apparatus.
[0072] Referring next to the embodiment shown in FIGS. 10-11, a
casting apparatus, shown as continuous casting apparatus 400
includes a mold, shown as mold 410, that is configured to receive
molten material 420 as part of a continuous casting process. In
another embodiment, the casting apparatus is a batch casting
apparatus that includes a mold configured to receive molten
material 420 as part of a batch casting process. As shown in FIG.
10, molten material 420 flows from a tundish 430 into mold 410. In
one embodiment, mold 410 includes a sidewall, shown as sidewall
412, that at least partially shapes a cast product, shown as cast
product 440. As shown in FIG. 10, cast product 440 includes first
end 442 having a vertical orientation and second end 444 having a
horizontal orientation. A plurality of guides, shown as rollers
450, facilitates the transition of cast product 440 between the
vertical and horizontal orientations. According to the embodiment
shown in FIG. 10, continuous casting apparatus 400 includes probe
460. As shown in the detail view of FIG. 11, probe 460 is
configured to engage cast product 440 with test signal 462 and
provide a sensing signal relating to a property of cast product
440.
[0073] Referring again to FIG. 11, processing circuit 470 is
coupled to probe 460. Processing circuit 470 may be implemented as
a general-purpose processor, an application specific integrated
circuit (ASIC), one or more field programmable gate arrays (FPGAs),
a digital-signal-processor (DSP), circuits containing one or more
processing components, circuitry for supporting a microprocessor, a
group of processing components, or other suitable electronic
processing components. According to the embodiment shown in FIG.
11, processing circuit 470 includes processor 472 and memory 474.
Processor 472 may include an ASIC, one or more FPGAs, a DSP,
circuits containing one or more processing components, circuitry
for supporting a microprocessor, a group of processing components,
or other suitable electronic processing components. In some
embodiments, processor 472 is configured to execute computer code
stored in memory 474 to facilitate the activities described herein.
Memory 474 may be any volatile or non-volatile computer-readable
storage medium capable of storing data or computer code relating to
the activities described herein. In one embodiment, memory 474 has
computer code modules (e.g., executable code, object code, source
code, script code, machine code, etc.) configured for execution by
processor 472. In some embodiments, processing circuit 470
represents a collection of processing devices (e.g., servers, data
centers, etc.). In such cases, processor 472 represents the
collective processors of the devices, and memory 474 represents the
collective storage devices of the devices. According to one
embodiment, processing circuit 470 is configured to determine a
volumetric temperature profile of cast product 440 during the
casting process by evaluating the plurality of sensing signals.
Processing circuit 470 may be configured to determine a control
variable using the volumetric temperature profile.
[0074] In one embodiment, probe 460 includes an ultrasound
transducer and test signal 462 includes a plurality of ultrasound
waves. By way of example, the plurality of ultrasound waves may be
produced as a plurality of beams (e.g., a plurality of non-linearly
coupled beams). Interaction of the ultrasound waves with cast
product 440 may produce a plurality of response signals. In one
embodiment, probe 460 is configured to receive the response
signals. The sensing signals provided by probe 460 may be related
to the response signals.
[0075] According to one embodiment, processing circuit 470 is
configured to determine the volumetric temperature profile of cast
product 440 based on the thermal variation of sound speed (i.e.,
waves may travel at a rate that varies as a function of
temperature). Cast product 440 may include a plurality of
constituents, and processing circuit 470 may be configured to
determine the volumetric temperature profile of cast product 440
based on a plurality of measured locations for the plurality of
constituents. By way of example, constituents within a
higher-temperature portion of cast product 440 may flow more
quickly or in a different direction than constituents within a
lower-temperature portion of cast product 440.
[0076] In another embodiment, probe 460 includes an electrical
signal generator and test signal 462 includes an electrical signal.
The sensing signals provided by probe 460 may be related to an
amount of current that passes through cast product 440. In one
embodiment, processing circuit 470 is configured to determine the
volumetric temperature profile of cast product 440 based on the
thermal variation of electrical conductivity. By way of example, a
higher-temperature portion of cast product 440 may have a
conductivity that is greater or lesser than a lower-temperature
portion of cast product 440.
[0077] In yet another embodiment, probe 460 includes a magnetic
field generator, and test signal 462 includes a magnetic field.
Processing circuit 470 may be configured to determine the
volumetric temperature profile of cast product 440 based on the
thermal variation of permeability. By way of example, a
higher-temperature portion of cast product 440 may have a
permeability that is greater than a lower-temperature portion of
cast product 440. In one embodiment, processing circuit 470
controls eddy current testing that measures a decay profile for
eddy currents within cast product 440, thereby facilitating
determination of the permeability and temperature for a portion of
cast product 440.
[0078] According to one embodiment, processing circuit 470 is
configured to use tomography to localize a line-sensed quantity. By
way of example, the line-sensed quantity may be a material density
(e.g., measured by optical or x-ray transmissivity, etc.). By way
of another example, the line sensed quantity may be at least one of
a porosity and a size distribution of material phases (e.g.,
measured by optical or ultrasound scattering from a beam, etc.). In
another embodiment, processing circuit 470 is configured to
evaluate the characteristics of a plane within cast product 440. In
still another embodiment, processing circuit 470 is configured to
evaluate the characteristics of a surface region on cast product
440.
[0079] According to one embodiment, processing circuit 470 is
configured to generate a real-time model of cast product 440 based
on the sensing signal. Processing circuit 470 may be configured to
determine the control variable using a simulation-based control
algorithm. In another embodiment, processing circuit 470 includes a
filter configured to relate a condition of cast product 440 to the
sensing signal. By way of example, the condition of the cast
product may include a phase, a phase distribution, a porosity, a
strength, a stress characteristic, a strain characteristic, a
fatigue characteristic, a creep characteristic, a vibrational mode,
a vibrational frequency, a ductility, a stress-strain
characteristic, and a uniformity of the cast product. By way of
another example, the condition of the cast product may include an
expense, a work input, a heating input, and a cooling input
required during the casting process. Processing circuit 470 may be
configured to determine the control variable using a filter-based
control algorithm. In still another embodiment, processing circuit
470 is configured to determine the control variable using computer
simulation (e.g., a parametric control algorithm, etc.).
[0080] As shown in FIGS. 10-11, continuous casting apparatus 400
includes regulation system 480. In one embodiment, regulation
system 480 is configured to modify cast product 440 during the
casting process as a function of the control variable. Regulation
system 480 may include an actuator, a thermal regulation system, an
electrical device, a magnetic field generator, or still another
apparatus.
[0081] Referring next to FIG. 12, method 500 for actively
controlling a casting process includes monitoring a property of a
cast product during the casting process with a sensor (510),
providing a corresponding sensing signal with the sensor (520),
generating a real-time model of the cast product based on the
corresponding sensing signal (530), and determining a control
variable using the real-time model of the cast product (540). In
one embodiment the control variable relates to a real-time
modification of the cast product.
[0082] Referring next to FIG. 13, method 600 for actively
controlling a casting process includes providing a mold configured
to at least partially shape a cast product as part of a casting
process (610), monitoring a property of the cast product during the
casting process with a sensor (620), providing a corresponding
sensing signal with the sensor (630), generating a real-time model
of the cast product based on the corresponding sensing signal
(640), determining a control variable using the real-time model of
the cast product (650), and modifying the cast product during the
casting process as a function of the control variable (660).
[0083] It is important to note that the construction and
arrangement of the elements of the systems and methods as shown in
the embodiments are illustrative only. Although only a few
embodiments of the present disclosure have been described in
detail, those skilled in the art who review this disclosure will
readily appreciate that many modifications are possible (e.g.,
variations in sizes, dimensions, structures, shapes and proportions
of the various elements, values of parameters, mounting
arrangements, use of materials, colors, orientations, etc.) without
materially departing from the novel teachings and advantages of the
subject matter recited. For example, elements shown as integrally
formed may be constructed of multiple parts or elements. It should
be noted that the elements and/or assemblies of the enclosure may
be constructed from any of a wide variety of materials that provide
sufficient strength or durability, in any of a wide variety of
colors, textures, and combinations. The order or sequence of any
process or method steps may be varied or re-sequenced, according to
alternative embodiments. Other substitutions, modifications,
changes, and omissions may be made in the design, operating
conditions, and arrangement of the preferred and other embodiments
without departing from scope of the present disclosure or from the
spirit of the appended claims.
[0084] The present disclosure contemplates methods, systems, and
program products on any machine-readable media for accomplishing
various operations. The embodiments of the present disclosure may
be implemented using existing computer processors, or by a special
purpose computer processor for an appropriate system, incorporated
for this or another purpose, or by a hardwired system. Embodiments
within the scope of the present disclosure include program products
comprising machine-readable media for carrying or having
machine-executable instructions or data structures stored thereon.
Such machine-readable media can be any available media that can be
accessed by a general purpose or special purpose computer or other
machine with a processor. By way of example, such machine-readable
media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical
disk storage, magnetic disk storage or other magnetic storage
devices, or any other medium which can be used to carry or store
desired program code in the form of machine-executable instructions
or data structures and which can be accessed by a general purpose
or special purpose computer or other machine with a processor. When
information is transferred or provided over a network or another
communications connection (either hardwired, wireless, or a
combination of hardwired or wireless) to a machine, the machine
properly views the connection as a machine-readable medium. Thus,
any such connection is properly termed a machine-readable medium.
Combinations of the above are also included within the scope of
machine-readable media. Machine-executable instructions include,
for example, instructions and data, which cause a general-purpose
computer, special purpose computer, or special purpose processing
machines to perform a certain function or group of functions.
[0085] Although the figures may show a specific order of method
steps, the order of the steps may differ from what is depicted.
Also two or more steps may be performed concurrently or with
partial concurrence. Such variation will depend on the software and
hardware systems chosen and on designer choice. All such variations
are within the scope of the disclosure. Likewise, software
implementations could be accomplished with standard programming
techniques with rule-based logic and other logic to accomplish the
various connection steps, processing steps, comparison steps, and
decision steps.
* * * * *