U.S. patent application number 16/488166 was filed with the patent office on 2020-01-30 for method for the optimized production of a component with at least one ancillary formed element.
This patent application is currently assigned to Salzgitter Flachstahl GmbH. The applicant listed for this patent is Salzgitter Flachstahl GmbH. Invention is credited to STEFAN MUTZE, MATTHIAS SCHNEIDER, SEBASTIAN WESTHAUSER.
Application Number | 20200030866 16/488166 |
Document ID | / |
Family ID | 61027740 |
Filed Date | 2020-01-30 |
United States Patent
Application |
20200030866 |
Kind Code |
A1 |
MUTZE; STEFAN ; et
al. |
January 30, 2020 |
METHOD FOR THE OPTIMIZED PRODUCTION OF A COMPONENT WITH AT LEAST
ONE ANCILLARY FORMED ELEMENT
Abstract
The invention relates to a method for the optimized production
of a component, in particular from steel, with at least one
secondary formed element, comprising the steps of a) providing a
blank which has been cut to size at room temperature from a strip
or a sheet and in which cut-outs and/or holes have optionally been
created by stamping or cutting operations; b) thermal treatment of
selected edge regions of the blank that have been cold-hardened by
the stamping or cutting operations, in which the edge regions are
heated to a temperature of at least 600.degree. C. for a maximum 10
seconds; c) forming the thermally treated edge regions of the blank
at ambient temperature to obtain a component with an unfinished
secondary formed element; characterized by an additional step d), a
calibrating step for obtaining the component with the secondary
formed element, wherein the unfinished secondary formed element is
formed at ambient temperature into a secondary formed element that
has an increased and/or more uniform wall thickness in comparison
with the unfinished secondary formed element.
Inventors: |
MUTZE; STEFAN; (Peine,
DE) ; SCHNEIDER; MATTHIAS; (Veltheim Ohe, DE)
; WESTHAUSER; SEBASTIAN; (Braunschweig, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Salzgitter Flachstahl GmbH |
38239 Salzgitter |
|
DE |
|
|
Assignee: |
Salzgitter Flachstahl GmbH
38239 Salzgitter
DE
|
Family ID: |
61027740 |
Appl. No.: |
16/488166 |
Filed: |
January 24, 2018 |
PCT Filed: |
January 24, 2018 |
PCT NO: |
PCT/EP2018/051680 |
371 Date: |
August 22, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B21D 28/10 20130101;
B21D 28/26 20130101; B21D 35/001 20130101; B21D 19/088 20130101;
B21D 22/022 20130101; B21K 23/04 20130101 |
International
Class: |
B21D 19/08 20060101
B21D019/08; B21D 22/02 20060101 B21D022/02 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 23, 2017 |
DE |
10 2017 103 743.8 |
Claims
1.-14. (canceled)
15. A method for the optimized production of a component, in
particular of steel, with an ancillary formed element, comprising
the steps of a) providing a blank cut from a strip or metal sheet
at room temperature and optionally produced with recesses and/or
openings by punching or cutting operations; b) temperature-treating
selected edge regions of the blank that have been strain-hardened
by the punching or cutting operations, by heating the edge regions
to a temperature of at least 600.degree. C. for a period of maximal
10 seconds; c) forming the temperature-treated edge regions of the
blank at ambient temperature to obtain a component with raw
ancillary formed element; and d) executing a calibration for
obtaining the component with ancillary formed element by forming
the raw ancillary formed element at ambient temperature into the
ancillary formed element which has increased and/or homogenized
wall thickness compared to the raw ancillary formed element.
16. The method of claim 15, wherein the ancillary formed element is
a collar or a flange.
17. The method of claim 15, further comprising, prior to the
temperature-treating step, forming selected edge regions of the
blank that have been strain hardened by the punching or cutting
operations at room temperature.
18. The method of claim 15, wherein the raw ancillary formed
element is generated in step c) by forming the edge regions in a
defined direction and wherein the formation of said edge regions in
step d) is implemented in a direction opposite to the defined
direction.
19. The method of claim 15, wherein the temperature-treating step
is carried out for a period of 0.02 to 10 seconds.
20. The method of claim 15, wherein the temperature-treating step
is carried out for a period of 0.1 to 2 seconds.
21. The method of claim 15, wherein the temperature-treating step
is carried out at a temperature of 600.degree. C. to a solidus
temperature.
22. The method of claim 15, wherein the temperature-treating step
is carried out at a temperature between a transformation
temperature Ac1 and a solidus temperature.
23. The method of claim 15, wherein the edge regions are heated to
the temperature of at least 600.degree. C. Inductively,
conductively, by radiation heating, or laser radiation.
24. The method of claim 15, further comprising coating the blank
with an organic and/or metallic coating.
25. The method of claim 15, wherein the temperature-treating step
of the edge regions, starting from an edge, takes place in a region
which corresponds at most to a thickness of the blank.
26. The method of claim 15, further comprising flushing a region
about a location of the temperature treatment during and optionally
before and/or after the temperature-treating step with inert gas
for protection against oxidation.
27. A component, in particular of steel, comprising an ancillary
formed element with high and/or homogeneous wall thickness, wherein
for the production of the component a blank is provided which is
cut at room temperature from a strip or a sheet metal and in which
recesses and/or openings are optionally produced by punching or
cutting operations, wherein a temperature treatment of selected
edge regions of the blank that have been strain hardened by the
punching or cutting operations is carried out, with the edge
portions being heated to a temperature of at least 600.degree. C.
for a period of maximal 10 seconds, wherein the temperature-treated
edge regions of the blank was formed at room temperature to obtain
a component with raw ancillary formed element, and wherein the raw
ancillary formed element was formed to obtain the component with
ancillary formed element at room temperature into an ancillary
formed element of increased and/or homogenized wall thickness
compared to the raw ancillary formed element.
28. The component of claim 27, wherein the ancillary formed element
is a collar or a flange.
29. The component of claim 27, produced from a steel with the
following alloy composition in wt.-%: TABLE-US-00002 C 0.01-0.2% Si
.sup. 0.2-4.0% Mn .sup. 0.5-4.0% Al 0.02-0.1 Ti 0.0-0.2 V 0.0-0.3
Nb 0.0-0.1
with optional addition of Cr, Ni, Mo, B, balance iron, including
impurities resulting from smelting.
30. A blank of steel for use in the production of a component with
at least one ancillary formed element, wherein the blank previously
cut at room temperature from a strip or a metal sheet is subjected,
after undergoing punching or cutting operations at room temperature
for realizing recesses or openings, in selected edge regions that
were strain hardened by the punching or cutting operations to a
temperature treatment in which the edge regions are heated of at
least 600.degree. C. for a period of a maximal 10 seconds, wherein
the temperature treated edge regions of the blank are formed at
room temperature to obtain a component with raw ancillary formed
element, and wherein the raw ancillary formed element is formed at
room temperature into an ancillary formed element having a wall
thickness which is increased and/or homogenized compared to the raw
ancillary formed element.
Description
[0001] The present invention relates to a method for the optimized
production of a component, in particular of steel, with at least
one ancillary formed element, in particular a collar or a flange,
which is characterized in particular by the fact that the geometry
of the ancillary formed element is deliberately adjustable and the
component can therefore be manufactured individually very precise
and for various applications. The component is further
characterized by the fact that it is formed in one piece with the
ancillary formed element and has a very high stability also in the
region of the formed edges.
[0002] In the following, a blank or sheet metal blank shall be
understood as relating to a cut of a sheet metal, in particular a
sheet steel. The sheet metal blanks can be uncoated or provided
with a metallic and/or organic corrosion protection coating.
[0003] In the following, a component shall be understood to relate
to a component which is produced from a sheet metal blank by being
formed using a forming tool at ambient temperature. Sheet metal
materials include any formable metal materials, in particular steel
however.
[0004] Such components are predominantly used in the automotive
construction, but also applications in the home appliance industry,
in mechanical engineering or civil engineering or in the field of
yellow are possible.
[0005] The hotly contested automotive market forces the
manufacturers to continuously look for solutions to reduce their
fleet consumption while maintaining a highest possible comfort and
occupant protection. Not only weight savings of all vehicle
components play hereby a crucial role, but also a most beneficial
behavior of the individual components at high static and dynamic
stress during operation as well as in the event of a crash.
[0006] Suppliers of source material attempt to meet the required
material demands by reducing the wall thicknesses of high strength
and super high strength steels, while at the same time improving
component behavior during production and operation.
[0007] These steels must therefore meet comparatively strict
demands in terms of strength, deformability, toughness, energy
absorption capability and corrosion resistance as well as their
workability, for example during cold forming with respect to the
fatigue behavior and during welding.
[0008] Among the afore-stated aspects, the production of components
of higher and high strength steels with yield strengths above 400
MPa, advantageously above 600 or above 800 MPa to about 1800 MPa or
even more, increasingly gains importance. For example, ferritic or
bainitic or dual phase steels with the following alloy composition
in weight-% find application:
TABLE-US-00001 C 0.01-0.2% Si .sup. 0.2-4.0% Mn .sup. 0.5-4.0% Al
0.02-0.1 Ti 0.0-0.2 V 0.0-0.3 Nb 0.0-0.1
with optional addition of Cr, Ni, Mo, B, balance iron, including
impurities resulting from smelting.
[0009] It is known for the production of a component to first cut
to size a sheet metal blank of hot or cold strip at room
temperature. Cutting processes involve oftentimes mechanical
separation processes, such as e.g. shearing or punching, but less
common also thermal separation processes, such as e.g. laser
cutting. Thermal separation processes are significantly more
cost-intensive compared to mechanical separation processes, so that
their use is contemplated only in exceptional cases.
[0010] After cutting, the cut blank is placed in a forming tool and
the finished component, such as e.g. a chassis carrier, is produced
in single or multi-stage forming steps.
[0011] During forming operation, the cutting edges, in particular
when being raised or placed up, e.g. collar operations in
perforated blanks, are particularly exposed to stress.
[0012] Before forming operation, various other optional
manufacturing steps, such as e.g. punching and cutting operations,
are implemented on the blank.
[0013] The cutting edges may have various preliminary damages.
These are caused on one hand by strain hardening of the material,
as a result of the mechanical separation, which represents a total
deformation up to material separation. On the other hand, a notch
effect may be encountered, which is due to the topography of the
cut surface.
[0014] Especially with the steels considered here, an increased
crack probability in the edge regions of these cutting edges is
thus encountered during the subsequent forming process.
[0015] The afore-mentioned preliminary damages to the sheet edges
can lead to premature failure during subsequent forming operations
or during operation of the component.
[0016] To minimize the edge crack sensitivity during cold forming
of shear-cut or punched sheet edges, approaches are known, for
example, involving changing of the alloy composition and material
processing (e.g. targeted adjustment of an optimized
microstructure) or relating to process engineering during cold
trimming of the blank (e.g. via modifications of cutting gap,
speed, multiple trimming, etc.).
[0017] These measures are either expensive and complex (e.g.
multi-stage cutting operations, maintenance of 3-D cutting tools,
etc.), or do not yet yield optimal results.
[0018] Furthermore, it is known from laid-open publication DE 10
2009 049 155 A1 to heat at least the region of the cutting edge to
a defined temperature and to execute the cutting process at this
temperature in order to improve the formability of the cut edges
and to thereby reduce or avoid the strain hardening in the region
of the cutting edge. The disadvantage here is the required high
technical and economic complexity to heat the metal sheet on one
hand, and the forced coupling of heating of the blank with
immediately subsequent cutting process, thus rendering the
production inflexible on the other hand.
[0019] Laid-open publication DE 10 2011 121 904 A1 further
discloses to cold-form a shear-cut sheet and, prior to further
forming operations, to locally heat the strain-hardened regions by
means of a laser with the objective of partial softening. The
disadvantage here is in particular the local softening, which
represents a discontinuity in terms of the often used high strength
and super high strength material, especially in stress situations
and under oscillatory stress. In addition, it is unclear where
exactly heating should occur and how the local heating with
temperature and time sequence should actually be implemented.
Furthermore, it is unclear how and to what extent partial softening
is able to improve formability of the already cold-formed metal
sheet.
[0020] Laid-open publication DE 10 2014 016 614 A1 describes a
method for the production of a component by forming a blank of
steel, wherein a cut blank, following optional punching and/or
cutting operations in the regions of the shear-cut edges, undergoes
a short temperature treatment (max. 10 seconds) of at least
600.degree. C. The heat-treated edges are then cold formed at any
time after being heated. Even though this method is basically
capable to increase formability of strain-hardened mechanically
separated sheet edges when compared to other previously known
methods, it is still desirable to be able to define and
deliberately adjust geometric boundary conditions of an ancillary
formed element produced by forming, in order to achieve a more
precise configuration and increased stability of the ancillary
formed element.
[0021] Laid-open publication DE 11 2007 000 239 T5 discloses a
method for producing a wheel disc. A flat disc blank is formed into
a bowl-shaped wheel disc. The bowl-shaped wheel disc is formed to
form spoke-forming regions adjacent to window-forming regions. A
window is formed in each of the window-forming regions in a
substantially vertical direction, wherein each window has a
respective outer edge proximate a continuous outer band around a
periphery of the wheel disc. The windows define a plurality of
spokes between adjacent windows. A circumferential length of each
of the windows along the outer band is preferably greater than a
circumferential length of each of the spokes. The outer edge is
partially formed by means of a forming tool for forming a
cylindrical shape, wherein the forming tool has an engagement
surface with an intermediate ledge for receiving a peripheral edge
of the outer band to reduce undulated deformations of the outer
band. The outer edge is then fully brought into a substantially
cylindrical shape by a cylindrical punch by being pulled axially
along its outer edge. With the invention, grooves and undulations
should be prevented when forming the collar.
[0022] Also this known method is not yet able to deliberately and
individually adjust the geometric boundary conditions, such as wall
thickness and wall height of a produced ancillary formed
element.
[0023] It is therefore the object of the present invention to
provide an alternative method for the production of a component, in
particular of steel with formed-on ancillary formed element,
wherein the geometric boundary conditions, e.g. the wall thickness
and/or the wall height of ancillary formed element, can be adjusted
deliberately and individually.
[0024] The invention solves this problem with the features of the
claims and in particular by providing a method for the optimized
production of a component having at least one ancillary formed
element with the steps of
a) providing a blank cut from a strip or metal sheet at room
temperature and optionally produced with recesses and/or openings
by punching or cutting operations; b) temperature treatment of
selected edge regions of the blank that have been strain-hardened
by the punching or cutting operations, wherein the edge regions are
heated to a temperature of at least 600.degree. C. for a period of
maximal 10 seconds; c) forming the temperature-treated edge regions
of the blank at ambient temperature to obtain a component with raw
ancillary formed element; d) calibration step for obtaining the
component with ancillary formed element, wherein the raw ancillary
formed element is formed at ambient temperature into an ancillary
formed element which has increased and/or homogenized wall
thickness compared to the raw ancillary formed element.
[0025] As ambient temperature, both the room temperature, for
example 20.degree. C., and the temperature of the forming tool are
considered. The temperature of the forming tool may lie well above
the room temperature.
[0026] The blank provided in step a) of the method according to the
invention has in the regions of its shear-cut edges an unwanted
strain-hardening, which considerably reduces formability of the
blank. This applies to both the shear-cut edge regions when cut
from the metal sheet or strip and the edge regions which are
shear-cut by a closed section or a punching operation and also the
edge portions which are shear-cut by an open cut or a cutting
operation.
[0027] For the purposes of the invention, a closed cut is
understood to relate to a punching operation or a cutting operation
having a starting point which is identical to the end point. The
result of such a closed section is therefore an opening in the
blank, for example a circular or polygonal, e.g. quadrangular
opening. By contrast, an open cut is a cutting operation having a
starting point which is not identical to the end point. The result
of such an open cut is therefore a shear-cut contour of any
geometry.
[0028] The process of shear cutting causes in the regions of the
involved edges a strain hardening in the respective material, which
is known to often lead to cracking in subsequent forming
processes.
[0029] As a result of the temperature treatment according to the
invention according to step b), the unwanted strain hardening can
be eliminated or at least greatly reduced, so that the material can
also be formed in the regions of the shear-cut edges, without
encountering an increased susceptibility to cracking. A short
temperature treatment for a period of maximal 10 seconds is already
sufficient to eliminate or reduce strain hardening. Preferably, the
temperature treatment lasts for a period of 0.02 to 10 seconds, and
more preferably for a period of 0.1 to 2 seconds.
[0030] The process window for the temperature to be reached in the
cutting edge region is moreover very large and includes a
temperature range of above 600.degree. C. up to the solidus
temperature of approx. 1500.degree. C., e.g. a range between the
transformation temperature Ac1 and the solidus temperature.
[0031] In any case, it is crucial that the temperature treatment
eliminates as far as possible the strain hardening introduced by
the cutting process. The heat treatment according to the invention
results in the region of the cutting edge in a same or higher
hardness compared to non-heat-treated base material. For example,
the Vickers hardness increases by up to 1000 HV.
[0032] Due to the elimination of strain hardening, the
temperature-treated edge regions of the blank in step c) of the
method according to the invention can be formed at room temperature
into a raw ancillary formed element with demanding geometry, for
example to a collar with a large collar height or a flange with a
large flange height. The production of such a demanding geometry is
not possible with most conventional methods, since the strain
hardening caused by the shear cutting of the edges allows only a
deformation of the edges to a relatively small extent.
[0033] While the method described in DE 10 2014 016 614 A1 is
generally also able to produce collars with a large collar height
and flanges with a large flange height, since this method also
includes the steps a to c of the method according to the invention.
However, it has been found that the wall thickness of the collar
and flanges thus produced is often not uniform. Furthermore, this
method is unable to allow adjustment of a defined height of the
ancillary formed elements, since the edge regions are formed
comparably undefined by the use of a widening tool, for example a
conical or cylindrical punch. In particular, due to their undefined
height and their non-uniform wall thickness, the ancillary formed
elements produced in this way are referred to herein as "raw
ancillary formed elements".
[0034] The invention now provides for a calibration step d) for
producing an ancillary formed element with a defined geometry, e.g.
with defined and uniform wall thickness and/or wall height. This is
an additional forming step at room temperature, which
chronologically takes place after the first forming step (step c of
the method according to the invention).
[0035] Surprisingly, it has been shown that in the calibration step
d) by forming in a direction which is at least partially in
opposition to the forming direction in step c), properties of the
ancillary formed element can be advantageously altered.
[0036] The forming process in step c) is usually implemented by
applying a forming tool in a so-called widening direction. For
example, to produce a collar or a flange, a punch is inserted into
a shear-cut or punched opening in the component, wherein by drawing
the punch in widening direction through the opening, the edge
regions are bent upward.
[0037] Since it is generally advantageous for various applications
of components but still difficult to achieve the highest possible
height of the respective ancillary formed element, it is first of
all absurd to again reduce this once realized height of ancillary
formed element by an additional forming step, e.g. by applying a
force on the height of the ancillary formed element in a direction
that counteracts the widening direction wholly or partially. That
this is possible at all is due only by the temperature treatment
according to the invention and the forming of the shear-cut edge
regions in accordance with the invention, by which ancillary formed
elements, e.g. edges, collars or flanges, can be produced with
significantly higher than average height. These ancillary formed
elements still have a sufficient height even after being formed in
opposition to the widening direction, and are characterized by
improved properties. It has been found that this forming process,
which corresponds in principle to a compression, enables
homogenization of the wall thickness of the ancillary formed
element on one hand and increase thereof on the other hand, which
both positively affect the properties of the component, e.g. its
stability and life. Furthermore, the additional forming step,
realized by a force applied in opposition to the preceding forming
direction, renders it possible to generate a defined height of the
ancillary formed element, in particular a defined edge height,
flange height or collar height. As a result of the implementation
of a defined adjustment of geometric boundary conditions of
ancillary formed elements by the additional forming step, this
forming step is referred to in accordance with the invention as a
calibration step.
[0038] A calibration step is also to be understood as a shaping of
edge regions with a force which is applied not completely but only
partially in opposition to the preceding forming operation in the
widening direction. Such a calibration step renders possible the
production of, for example, ancillary formed elements with edges
that are angled by 90.degree.. As a result of this calibration cut,
adjustment of the conicity and/or the cylindricity can
advantageously be tailored, so that expensive reworking processes
can be reduced to a minimum.
[0039] In concrete terms, a defined adjustment of geometric
boundary conditions, for example of a collar, can be:
1. the height of the collar 2. the wall thickness over the
circumference and the height of the collar 3. the shape accuracy
(cylindricity/conicity) of the collar, achieved by: [0040] a) a
matching punch geometry for varying the frictional force between
punch and material (1, 2) [0041] b) a matching drawing gap between
punch and die for targeted ironing of the material (1, 2) [0042] c)
introduction of a calibration step with regard to (2, 3)
calibration step may be with respect to the long collar: [0043] in
the direction of the widening direction (also by means of reduced
drawing gap--ironing) [0044] in opposition to the widening
direction for upsetting the material with the objective to
increase/homogenize the wall thickness [0045] in opposition to the
widening direction for the generation of possible collar variants
e.g. flange, flaring, defined buckling [0046] d) combination of the
variants a, b, c in combination with heating of the cutting edges
in accordance with the invention to allow a much higher forming
operation and improved quality with respect to 2 and 3, also as
multi-stage drawing processes (flat punch to draw material forward,
Tracktrix punch to finally form collar)
[0047] According to an advantageous refinement of the invention,
the method according to the invention has a further forming step,
in which selected edge regions of the blank, strain hardened by the
punching or cutting operations, can be formed at room temperature.
This further forming step takes place after cutting of the blank
and possible punching and/or cutting operations and prior to the
temperature treatment of the edge regions. As a result of the
additional forming step, the strain hardening, encountered by the
cut and the optional punching and/or cutting operations in the
material, is even further increased, but eliminated again by the
subsequent temperature treatment according to the invention.
[0048] In a modified embodiment, the method according to the
invention includes between steps a) and b) not only the one
additional forming step, but also any number of further
consequences of the inventive temperature treatment of the edge
regions at a temperature of at least 600.degree. C. for a period of
maximal 10 seconds and another forming step. In this way, it is
possible to further form the material in each forming step, and to
remove the interfering factors caused by the forming process, such
as strain hardening, microstructure damages, and adverse contour
changes such as, e.g. microcracks.
[0049] The individual forming and temperature treatment steps of
the method according to the invention can be implemented at any
time, i.e. temporally decoupled from one another.
[0050] The forming steps of the method according to the invention
can advantageously be executed with forming tools, e.g. cylindrical
or conical punches, that already exist in the production. As a
result, no expensive investment costs for carrying out the method
according to the invention are necessary.
[0051] The method according to the invention is particularly
applicable to any shear-cut material edges, in particular to
punched holes and edges with any contour. As a result of the
increased formability in accordance with the invention, it becomes
possible to also produce complex geometries that require, for
example, several forming steps. Even complex components can be
produced in one piece, eliminating the need for additional joining
operations.
[0052] The temperature treatment is preferably carried out in the
method according to the invention over the entire thickness of the
blank and in plane direction of the blank in a region which
corresponds at most to the thickness thereof. The duration of the
temperature treatment depends on the type of heat treatment
process.
[0053] Heating itself can be implemented in any desired manner, for
example, conductively, inductively via radiation heating, or by
laser processing. Especially suitable for temperature treatment is
conductive heating, as used for example in the automotive industry
in many cases as demonstrated by the example of spot welds.
[0054] Advantageously, the use of a spot welding machine for
example with rather short treatment times for the treatment of
punched holes in the blank is suitable, whereas at longer edge
portions to be treated, the inductive method, radiation heating or
laser processing with longer treatment times are considered.
[0055] Thus, the heat input is very concentrated into the
shear-affected cutting edge regions and is therefore accompanied
with a comparatively little energy consumption, in particular with
regard to processes in which the entire blank is subjected to a
heating or which find application in a stress relief heat treatment
that is more time consuming by orders of magnitude.
[0056] According to one embodiment of the method of the invention,
the blank has a metallic and/or organic coating. This coating may
contain or be made of zinc, magnesium, aluminum and/or silicon. The
blank itself can e.g. be rolled flexibly with different thicknesses
or be joined from cold or hot strip of same or different thickness
and/or quality. The invention is applicable to hot or cold rolled
steel strips of soft to high strength steels.
[0057] As higher strength steels, all single-phase as well as
multi-phase steel grades find application. These include
micro-alloyed, higher strength steel grades as well as bainitic,
ferritic or martensitic grades as well as dual phases, complex
phases and TRIP steels.
[0058] According to a possible embodiment of the method, to protect
against oxidation during and optionally before and/or after the
temperature treatment, the region around the location of the
temperature treatment can be flushed by an inert gas.
[0059] In view of the short temperature treatment period of maximal
10 seconds, the method according to the invention can be integrated
as an intermediate operating step in a series production which
specifies a clock rate in the range of 0.1 to 10 seconds. In
particular, the production of sheet metal components in the
automotive sector in several successive steps thus represents a
predestined field of application of the method according to the
invention.
[0060] The invention also relates to a component having at least
one ancillary formed element with high and/or homogeneous wall
thickness, wherein for the production of the component a blank is
provided which has been cut at room temperature from a strip or
sheet metal and has been optionally produced by punching or cutting
operations with recesses and/or openings, wherein a temperature
treatment of selected edge regions of the blank that have been
strain hardened by the punching or cutting operations is carried
out, with the edge portions being heated to a temperature of at
least 600.degree. C. for a period of maximal 10 seconds, wherein
the temperature-treated edge regions of the blank were formed at
room temperature to obtain a component with raw ancillary formed
element, and wherein the raw ancillary formed element was formed to
obtain the component with ancillary formed element at room
temperature into an ancillary formed element of increased and/or
homogenized wall thickness compared to the raw ancillary formed
element.
[0061] In an advantageous refinement of the invention, it is
provided that the formed edge regions are repeatedly heat-treated
and reshaped.
[0062] Preferred components are e.g. chassis components of hot
sheet or cold sheet with attached ancillary formed elements, in
particular collar, flanges and/or edges, which are obtainable by a
method according to the invention.
[0063] Finally, the invention also relates to the use of a blank of
steel for producing a component with at least one ancillary formed
element, wherein the blank previously cut at room temperature from
a strip or a metal sheet is subjected after optional further
manufacturing steps are carried out at room temperature, such as
e.g. punching or cutting operations for realizing recesses or
openings, in selected edge regions that were strain hardened by the
punching or cutting operations to a temperature treatment in which
the edge regions are heated of at least 600.degree. C. for a period
of a maximal 10 seconds, wherein the temperature-treated edge
regions of the blank are formed at room temperature to obtain a
component with raw ancillary formed element, and wherein the raw
ancillary formed element is formed at room temperature into an
ancillary formed element having a wall thickness which is increased
and/or homogenized compared to the raw ancillary formed element. In
an advantageous refinement of the invention, it is provided that
here too the formed edge regions are repeatedly heat-treated and
reshaped.
[0064] The features of the invention as disclosed in the above
description and in the claims may be essential individually as well
as in any desired combinations for the realization of the invention
in its various embodiments.
* * * * *