U.S. patent application number 14/698937 was filed with the patent office on 2016-05-19 for method for surface-treating forging member.
This patent application is currently assigned to MACOHO CO., LTD.. The applicant listed for this patent is MACOHO CO., LTD., NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY. Invention is credited to Kunio HAYAKAWA, Sachito MATSUBARA, Tamotsu NAKAMURA.
Application Number | 20160136722 14/698937 |
Document ID | / |
Family ID | 55960874 |
Filed Date | 2016-05-19 |
United States Patent
Application |
20160136722 |
Kind Code |
A1 |
MATSUBARA; Sachito ; et
al. |
May 19, 2016 |
METHOD FOR SURFACE-TREATING FORGING MEMBER
Abstract
An objective of the present invention is to provide an
innovative method for surface-treating a forging member, the method
exhibiting unprecedented operations and effects. The present
invention is a method for surface-treating a forging member (1),
wherein a slurry (4) comprising a mixture of a liquid (2) and an
abrasive (3) is mixed with pressurized air and sprayed on a surface
(1a) of the forging member (1), and innumerable recesses (5)
measuring 0.5-2.00 .mu.m in depth and 75-150 .mu.m in opening width
are provided on the surface (1a) of the forging member (1).
Inventors: |
MATSUBARA; Sachito;
(Nagaoka-shi, JP) ; NAKAMURA; Tamotsu;
(Shizuoka-shi, JP) ; HAYAKAWA; Kunio;
(Shizuoka-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MACOHO CO., LTD.
NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY |
Nagaoka-shi
Shizuoka-shi |
|
JP
JP |
|
|
Assignee: |
MACOHO CO., LTD.
Nagaoka-shi
JP
NATIONAL UNIVERSITY CORPORATION SHIZUOKA UNIVERSITY
Shizuoka-shi
JP
|
Family ID: |
55960874 |
Appl. No.: |
14/698937 |
Filed: |
April 29, 2015 |
Current U.S.
Class: |
451/39 ;
451/40 |
Current CPC
Class: |
B21J 1/02 20130101; B24C
1/06 20130101; B24C 11/00 20130101; B21J 3/00 20130101 |
International
Class: |
B21J 1/02 20060101
B21J001/02; B24C 11/00 20060101 B24C011/00; B24C 1/06 20060101
B24C001/06 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 19, 2014 |
JP |
2014-234350 |
Claims
1. A method for surface-treating a forging member, characterized in
that a slurry comprising a mixture of a liquid and an abrasive is
mixed with pressurized air and sprayed on a surface of the forging
member, and innumerable recesses measuring 0.5-2.00 .mu.m in depth
and 75-150 .mu.m in opening width are provided on the surface of
the forging member.
2. The method for surface-treating a forging member according to
claim 1, characterized in that the forging member is made from
chromium-molybdenum steel.
3. The method for surface-treating a forging member according to
claim 1, characterized in that a stainless-steel abrasive having an
average particle diameter of approximately 150 .mu.m is adopted as
the abrasive.
4. The method for surface-treating a forging member according to
claim 2, characterized in that a stainless-steel abrasive having an
average particle diameter of approximately 150 .mu.m is adopted as
the abrasive.
Description
TECHNICAL FIELD
[0001] The present invention relates to a method for
surface-treating a forging member.
BACKGROUND ART
[0002] Cold-forging, adopted as a method for manufacturing machine
components, is limited to a greater extent than manufacturing by
cutting in terms of the forms that can be manufactured.
Nevertheless, cold-forging has numerous merits, making it possible
to mass-produce the same forms, obtain higher strength, shorten
machining time, and economize on materials, among other
benefits.
[0003] It has traditionally been desirable to lubricate the surface
of a columnar forging member serving as a workpiece to be
cold-forged (such lubrication commonly being referred to as
bonderizing, which is a lubricating-film-attaching treatment) and
firmly anchor a lubrication film on the surface of the forging
member in order to improve the die-releasing properties, to prevent
damage to the mold due to heat or contact pressure arising during
processing, as well as to prevent damage to the forging member
itself.
[0004] The inventor(s) proposed workpiece surface treatment devices
disclosed in JP-A 2007-38309 and U.S. Pat. No. 5,523,507. Prior to
attaching a lubricating film to the surface of a forging member
serving as a workpiece, these devices spray a slurry comprising a
mixture of a liquid and an abrasive to perform a wet-blasting
treatment on the surface of the forging member.
[0005] By performing this wet-blasting treatment, removal of
oxidized films, oil, and other pollutants attached to the surface
of the forging member is reliably and satisfactorily performed, and
minute irregularities are formed on the surface of the forging
member, whereby a lubricating film is satisfactorily established so
as to not readily peel off.
PRIOR ART DOCUMENTS
Patent Documents
[0006] [Patent Document 1] JP-A 2007-38309
[0007] [Patent Document 2] Patent No. 5523507
DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
[0008] As a result of further research and development regarding
surface treatment of forging members such as is described above,
the inventor(s) developed an innovative method for surface-treating
a forging member, the method exhibiting unprecedented operations
and effects.
Means for Solving the Problem
[0009] The main points of the present invention are described below
with reference to the attached drawings.
[0010] The present invention relates to a method for
surface-treating a forging member 1, the method being characterized
in that a slurry 4 comprising a mixture of a liquid 2 and an
abrasive 3 is mixed with pressurized air and sprayed on a surface
1a of the forging member 1, and innumerable recesses 5 measuring
0.5-2.00 .mu.m in depth and 75-150 .mu.m in opening width are
provided on the surface 1a of the forging member 1.
[0011] The present invention also relates to a method for
surface-treating a forging member according to the first aspect,
characterized in that the forging member 1 is made from
chromium-molybdenum steel.
[0012] The present invention also relates to a method for
surface-treating a forging member according to either of the first
and second aspects, characterized in that a stainless-steel
abrasive having an average particle diameter of approximately 150
.mu.m is adopted as the abrasive 3.
Effect of the Invention
[0013] Because the present invention is configured as described
above, this innovative method for surface-treating a forging member
exhibits the satisfactory establishment of a lubricating film so
that the lubricating film formed on the surface of the forging
member does not readily peel off, among other unprecedented
operations and effects.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic view of a device for implementing the
method for surface-treating a forging member as pertains to the
present example;
[0015] FIG. 2 is a schematic view showing the state of a
surface-treated forging member in the present example;
[0016] FIG. 3 is a partial enlarged view of the surface of the
surface-treated forging member in the present example;
[0017] FIG. 4 is a schematic view illustrating conditions of
testing that indicates the effectiveness of the present
example;
[0018] FIG. 5 is a schematic view showing a test of the performance
of a forging member using a forward rod/backward can extrusion
tester;
[0019] FIG. 6 is a schematic view showing a test of the performance
of a forging member using a forward rod/backward can extrusion
tester;
[0020] FIG. 7 is a schematic view illustrating test results that
indicate the effectiveness of the present example;
[0021] FIG. 8 is a schematic view illustrating test results that
indicate the effectiveness of the present example;
[0022] FIG. 9 is a schematic view illustrating test results that
indicate the effectiveness of the present example;
[0023] FIG. 10 is a schematic view illustrating test results that
indicate the effectiveness of the present example;
[0024] FIG. 11 is a schematic view illustrating test results that
indicate the effectiveness of the present example;
[0025] FIG. 12 is a schematic view illustrating test results that
indicate the effectiveness of the present example; and
[0026] FIG. 13 is a schematic view illustrating test results that
indicate the effectiveness of the present example.
BEST MODE FOR CARRYING OUT THE INVENTION
[0027] Preferred embodiments of the present invention are briefly
described below with reference to the diagrams while indicating the
action of the present invention.
[0028] In the present invention, a slurry 4 comprising a mixture of
a liquid 2 and an abrasive 3 is mixed with pressurized air and
sprayed on a surface of a forging member 1, and innumerable
recesses 5 measuring 0.5-2.00 .mu.m in depth and 75-150 .mu.m in
opening width are provided on the surface of the forging member
1.
[0029] The forging member 1 comprising the innumerable recesses 5
does not readily lose lubricity once the lubricating treatment has
been performed, and is highly exceptional as a raw material for
forging.
Examples
[0030] A specific example of the present invention is described
below with reference to the diagrams.
[0031] The present example is a method for surface-treating a
transported columnar forging member 1, a surface treatment being
performed on a surface 1a of the forging member 1. The forging
member 1 is columnar and is made from metal (chromium-molybdenum
steel). In the present document, "columnar" refers to a long shape
of circular cross-section; in the broadest sense, "columnar"
includes cylindrical shapes having hollow interiors.
[0032] Specifically, the method for surface-treating a forging
member 1 as pertains to the present example is performed using the
surface treatment device 10 disclosed in U.S. Pat. No.
5,523,507.
[0033] The surface treatment device 10 is equipped with a
transportation part 12 for transporting the columnar forging member
1 on a base 11, as illustrated in FIG. 1, and a surface treatment
part for performing wet-blasting treatment and other treatments on
the forging member 1 transported by the transportation part 12.
[0034] Specifically, the surface treatment part is configured from
a wet-blasting treatment part 13, and other treatment parts (a
cleaning treatment part, a hot-water washing part, a lubrication
treatment part, and a drying treatment part) (not shown).
[0035] The wet-blasting treatment part 13 is provided to the base
11, over which the columnar forging member 1 is caused to pass, as
shown in FIG. 1. The wet-blasting treatment part 13 is equipped
with a slurry-spraying part 14, a slurry reservoir part 15 arranged
at a position below the slurry-spraying part 14, and a
slurry-transporting part 17 for transporting a slurry 4 from the
slurry reservoir part 15 to the slurry-spraying part 14 via a pump
device 16, and is configured such that the slurry 4 sprayed from
the slurry-spraying part 14 is delivered to the slurry reservoir
part 15 and reused.
[0036] The slurry-spraying part 14 is configured from a wide spray
nozzle arranged above the transportation part 12 for transporting
the columnar forging member 1, as shown in FIG. 1.
[0037] The slurry-transporting part 17 described above is connected
to the spray nozzle, and a compressed-air-transporting part 19
provided in a separate circuit and extending from a
compressed-air-supplying part 18 is connected to the spray nozzle,
the spray nozzle being configured such that the slurry 4 supplied
from the slurry-transporting part 17 is accelerated by compressed
air supplied from the compressed-air-transporting part 19 and is
sprayed from the spray nozzle at a prescribed spraying speed.
[0038] The slurry 4 used in the present example is a mixture of a
liquid 2 and a fine-particle abrasive 3.
[0039] The surface treatment used on the forging member 1 using the
surface treatment device 10 comprising the configuration described
above will now be described.
[0040] The surface 1a of the columnar forging member 1 transported
by the transporting part 12 is appropriately treated by the surface
treatment part.
[0041] Specifically, once the columnar forging member 1 transported
by the transporting part 12 passes the wet-blasting treatment part
13, the slurry 4 is sprayed to blast the entire surface 1a
(peripheral and lengthwise-end surfaces) of the columnar forging
member 1, and innumerable minute recesses 5 are formed on the
entire surface 1a (peripheral and lengthwise-end surfaces).
[0042] Next, once the columnar forging member 1 that has been
blasted by the wet-blasting treatment part 13 passes the cleaning
treatment part, the columnar forging member 1 is sprayed with
cleaning fluid, whereby the forging member 1 is washed with water
(to remove the slurry, chips, and the like).
[0043] Next, once the columnar forging member 1 that has been
washed by the cleaning treatment part passes the hot-water washing
part, the columnar forging member 1 is sprayed with hot water,
whereby the forging member 1 is washed with water and
heat-treated.
[0044] Next, once the columnar forging member 1 that has been
washed and heat-treated by the hot-water washing part passes the
lubrication treatment part, the columnar forging member 1 is coated
with lubricant (e.g., metallic soap), whereby the forging member 1
is lubricated.
[0045] Next, once the columnar forging member 1 that has been
lubricated by the lubrication treatment part passes the drying
treatment part, the columnar forging member 1 is blown with hot
air, whereby the forging member 1 is dried (solidifying the
lubricant), and a lubricating film is formed on the entire surface
1a (peripheral and lengthwise-end surfaces) of the columnar forging
member 1.
[0046] The columnar forging member 1 that has been dried by the
drying treatment part is then guided out of the surface treatment
device 10 by a guiding part. The lubricating film is satisfactorily
established on the entire surface 1a (peripheral and lengthwise-end
surfaces) of the guided columnar forging member 1.
[0047] In the present example, innumerable (approximately 74,000)
recesses 5 (pyramid-shaped recesses) are formed on the surface 1a
of the forging member 1 having the raw materials and size described
below, the recesses 5 measuring 0.5-2.00 .mu.m in depth, 75-150
.mu.m in opening width, and 0.006-0.023 mm.sup.2 in area, the
forging member 1 being highly exceptional.
[0048] This is confirmed by the testing described below.
[0049] Specifically, first, an abrasive A (50-.mu.m stainless-steel
abrasive), an abrasive B (150-.mu.m stainless-steel abrasive), an
abrasive C (210-.mu.m stainless-steel abrasive), an abrasive D
(320-.mu.m stainless-steel abrasive), an abrasive E (250-.mu.m
alumina abrasive), and an abrasive F (300-.mu.m steel abrasive) are
prepared. The abrasives A-E are used to treat the forging member 1
(chromium-molybdenum steel, SCM420, 19.9 mm in diameter, 20 mm
long, approximately 1,030 mm.sup.2 in surface area) using the
surface treatment device 10 described above (the abrasive F is used
to perform shot-blasting), and the amounts of the resulting forging
member 1 extruded forward and backward are measured using a forward
rod/backward can extrusion tester(see FIGS. 4 and 5).
[0050] FIG. 7 shows the relationship between the abrasives A-F and
the forward extrusion amount, and FIG. 8 shows the relationship
between the abrasives A-F and the backward extrusion amount.
[0051] When the punch stroke in forward rod/backward can extrusion
is fixed, the frictional resistance of the surface decreases in
correspondence with an increase in the forward extrusion amount and
a decrease in the backward extrusion amount; ordering the abrasive
B, the abrasive C, the abrasive D, the abrasive E, the abrasive F,
and the abrasive A in the stated order results in the best forward
extrusion amount and backward extrusion amount as well as low
frictional resistance of the surface.
[0052] Specifically, a forging member 1 treated using the abrasive
B has more forward elongation and less backward elongation than
does a forging member 1 treated using another abrasive;
accordingly, it was evident that the frictional resistance in the
surface 1a of the forging member 1 treated using the abrasive B is
low. It is apparent from these results that the molding load is
strongly affected by the abrasive used.
[0053] FIG. 9 shows the relationship between the maximum load
during cold-forging molding and the forward extrusion amount.
[0054] The forging member 1 treated using abrasive B described
above has a lower maximum load during cold-forging molding than
does a forging member 1 treated using another abrasive.
[0055] Specifically, the forging member 1 comprising a surface 1a
in which a high forward extrusion amount is produced results in a
lower maximum load during cold-forging molding, the maximum load
during cold-forging molding and the extrusion amounts being
approximately inversely proportional, as predicted.
[0056] FIG. 10 shows the relationship between the forward extrusion
amount and the depth (H) of the recesses 5 produced in the end
surfaces of the forging member 1 when surface treatment is
performed on the forging member 1 using the abrasives A-F, and FIG.
11 shows the relationship between the forward extrusion amount and
the opening width (W) of the recesses 5 produced in the end
surfaces of the forging member 1 when surface treatment is
performed on the forging member 1 using the abrasives A-F.
[0057] As is apparent from FIG. 10, the depth of the recesses 5
produced by treatment using the abrasive B is 0.5 .mu.m when the
air pressure is 0.2 MPa, and is 1.5 .mu.m when the air pressure is
0.4 MPa. As is apparent from FIG. 11, the opening width of the
recesses 5 produced by treatment using the abrasive B is 150 .mu.m
when the air pressure is 0.2 MPa, and is 140 .mu.m when the air
pressure is 0.4 MPa.
[0058] FIG. 12 shows the relationship between the forward extrusion
amount and the depth (H) of the recesses 5 produced in the side
surface of the forging member 1 when surface treatment is performed
on the forging member 1 using the abrasives A-F, and FIG. 13 shows
the relationship between the forward extrusion amount and the
opening width (W) of the recesses 5 produced in the side surface of
the forging member 1 when surface treatment is performed on the
forging member 1 using the abrasives A-F.
[0059] As is apparent from FIG. 12, the depth of the recesses 5
produced by treatment using the abrasive B is 0.5 .mu.m when the
air pressure is 0.2 MPa, and is 2.00 .mu.m when the air pressure is
0.4 MPa. As is apparent from FIG. 13, the opening width of the
recesses 5 produced by treatment using the abrasive B is 75 .mu.m
when the air pressure is 0.2 MPa, and is 125 .mu.m when the air
pressure is 0.4 MPa.
[0060] The testing described above makes it possible to confirm
that a forging member 1 treated using an abrasive B determined to
be optimal and comprising innumerable recesses 5 produced in a
surface 1a of the forging member 1, the recesses 5 measuring
0.5-2.00 .mu.m in depth and 75-150 .mu.m in opening width, does not
readily lose lubricity once a lubricating treatment has been
performed, and is highly exceptional as a raw material for
cold-forging.
[0061] Because the present example is configured as described
above, a slurry 4 comprising a mixture of a liquid 2 and an
abrasive 3 is mixed with pressurized air and sprayed on a surface
of a forging member 1, and innumerable recesses 5 measuring
0.5-2.00 .mu.m in depth and 75-150 .mu.m in opening width are
provided on the surface of the forging member 1.
[0062] The forging member 1 comprising the innumerable recesses 5
does not readily lose lubricity once the lubricating treatment has
been performed, and is highly exceptional as a raw material for
forging.
[0063] Because the forging member 1 is made from
chromium-molybdenum steel, the present example can reliably exhibit
the operations and effects described above.
[0064] Because a stainless-steel abrasive having an average
particle diameter of approximately 150 .mu.m is adopted as the
abrasive 3, the present example can reliably exhibit the operations
and effects described above.
[0065] The present invention is not limited to the present example;
the specific configuration of the configuration requirements can be
optimized.
* * * * *