U.S. patent application number 16/099364 was filed with the patent office on 2019-07-11 for niobium and chromium low alloy carbon steel for high wear resistant automotive chain link plates.
The applicant listed for this patent is BorgWarner Inc.. Invention is credited to Matthew E. JUNKER, Yumin WANG.
Application Number | 20190211415 16/099364 |
Document ID | / |
Family ID | 60266717 |
Filed Date | 2019-07-11 |
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United States Patent
Application |
20190211415 |
Kind Code |
A1 |
WANG; Yumin ; et
al. |
July 11, 2019 |
NIOBIUM AND CHROMIUM LOW ALLOY CARBON STEEL FOR HIGH WEAR RESISTANT
AUTOMOTIVE CHAIN LINK PLATES
Abstract
Niobium chromium low allow carbon steel for automotive chain
link plates has improved wear resistance. In one preferred
embodiment, the steel composition includes niobium, chromium,
carbon, iron, and any impurities. One preferred composition
including these components includes, by weight percentage,
approximately 0.25% to 0.75% carbon, approximately 0.20% to 2.0%
chromium, approximately 0.26% to 1.5% niobium, and the remaining
component of the composition is iron. Trace amounts of impurities
may also be present. In another embodiment, a steel composition
includes, by weight percentage, approximately 0.25% to 0.75%
carbon, approximately 0.2% to 1.0% manganese, approximately 0.05%
to 0.60% silicon, approximately 0.26% to 1.5% niobium,
approximately 0.20% to 2.0% chromium, up to approximately 0.30%
aluminum, up to approximately 0.03% phosphorus, up to approximately
0.03% sulfur, and a remainder of the composition being iron and any
other impurities.
Inventors: |
WANG; Yumin; (Ithaca,
NY) ; JUNKER; Matthew E.; (Cortland, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BorgWarner Inc. |
Auburn Hills |
MI |
US |
|
|
Family ID: |
60266717 |
Appl. No.: |
16/099364 |
Filed: |
April 28, 2017 |
PCT Filed: |
April 28, 2017 |
PCT NO: |
PCT/US2017/030000 |
371 Date: |
November 6, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62333950 |
May 10, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16G 13/04 20130101;
C22C 38/26 20130101; C21D 1/25 20130101; C21D 1/22 20130101; F16G
13/08 20130101; C21D 6/002 20130101; C21D 9/0087 20130101; C22C
38/06 20130101; C21D 6/008 20130101; F16G 13/06 20130101; C22C
38/04 20130101; C21D 6/005 20130101; C21D 1/20 20130101; F16G 15/12
20130101; C22C 38/02 20130101 |
International
Class: |
C21D 9/00 20060101
C21D009/00; C22C 38/02 20060101 C22C038/02; C22C 38/04 20060101
C22C038/04; C22C 38/06 20060101 C22C038/06; C22C 38/26 20060101
C22C038/26; C21D 1/22 20060101 C21D001/22; C21D 1/25 20060101
C21D001/25 |
Claims
1.-10. (canceled)
11. A chain link comprising a steel composition comprising, by
weight percentage, approximately 0.25% to 0.75% carbon,
approximately 0.26% to 1.5% niobium, approximately 0.20% to 2.0%
chromium, iron and any impurities.
12. The chain link of claim 11, wherein the chain link has a
hardness of HRc 50 to 60.
13. The chain link of claim 12, wherein the chain link has a
hardness of HRc 52 to 58.
14. The chain link of claim 11, wherein the weight percentage of
carbon in the composition ranges from approximately 0.5% to
0.6%.
15. The chain link of claim 11, wherein the weight percentage of
chromium in the composition ranges from approximately 0.4% to
0.6%.
16. The chain link of claim 11, wherein the weight percentage of
niobium in the composition is greater than 0.5%.
17. The chain link of claim 11, wherein the weight percentage of
niobium in the composition ranges from approximately 0.26% to
0.8%.
18. The chain link of claim 11, wherein the composition further
comprises, by weight percentage, approximately 0.2% to 1.0%
manganese.
19. The chain link of claim 11, wherein the composition further
comprises, by weight percentage, approximately 0.05% to 0.60%
silicon.
20. The chain link of claim 11, wherein the composition further
comprises at least one impurity, by weight percentage, selected
from the group consisting of: a) up to approximately 0.3% aluminum;
b) up to approximately 0.03% phosphorus; c) up to approximately
0.03% sulfur; and d) any combination of up to approximately 0.3%
aluminum, up to approximately 0.03% phosphorus and up to
approximately 0.03% sulfur.
21. The chain link of claim 11, wherein the composition further
comprises approximately 0.2% to 1.0% manganese and approximately
0.05% to 0.60% silicon.
22.-36. (canceled)
37. A chain link comprising a composition comprising, by weight
percentage, approximately 0.25% to 0.75% carbon, approximately 0.2%
to 1.0% manganese, approximately 0.05% to 0.60% silicon,
approximately 0.26% to 1.5% niobium, approximately 0.20% to 2.0%
chromium, up to approximately 0.30% aluminum, up to approximately
0.03% phosphorus, up to approximately 0.03% sulfur, and a remainder
of the composition being iron and any other impurities.
38. The chain link of claim 37, wherein the chain link has a
hardness of HRc 50 to 60.
39. The chain link of claim 38, wherein the chain link has a
hardness of HRc 52 to 58.
40. A chain that includes a plurality of links, each link
comprising a steel composition comprising, by weight percentage,
approximately 0.25% to 0.75% carbon, approximately 0.2% to 1.0%
manganese, approximately 0.05% to 0.60% silicon, approximately
0.26% to 1.5% niobium, approximately 0.20% to 2.0% chromium, up to
approximately 0.30% aluminum, up to approximately 0.03% phosphorus,
up to approximately 0.03% sulfur, and a remainder of the
composition being iron and any other impurities.
41. The chain of claim 40, wherein the links have a hardness of HRc
50 to 60.
42. The chain of claim 41, wherein the links have a hardness of HRc
52 to 58.
43. A method of producing a chain link, comprising the step of heat
treating a steel composition comprising by weight percentage,
approximately 0.25% to 0.75% carbon, approximately 0.2% to 1.0%
manganese, approximately 0.05 to 0.60% silicon, approximately 0.26%
to 1.5% niobium, approximately 0.20 to 2.0% chromium, up to
approximately 0.30% aluminum, up to approximately 0.03% phosphorus,
up to approximately 0.03% sulfur, and a remainder of the
composition being iron and any other impurities, to a hardness of
HRc 50 to 60.
44. The method of claim 43, wherein the heat treating step uses a
method selected from the group consisting of oil quenching and
tempering, salt bath austempering, and salt bath martempering.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The invention pertains to the field of steel compositions.
More particularly, the invention pertains to steel compositions for
automotive chain link plates.
Description of Related Art
[0002] A lot of effort has been put into developing wear resistant
chains. One desire is to reduce wear and frictional losses for the
next generation of engine timing chains to be used in gasoline
direct injection (DI) engines and diesel engines. Current
production chains in these types of engines have high wear or chain
elongations and friction losses, which result in poor engine fuel
efficiency and high emission, or even engine failure due to the
malfunction of elongated chains which can cause tooth jump that
leads to vehicle safety concerns. The prior art has mainly seen
chain pin developments such as vanadium carbide (VC) pins or VC
coated pins and stainless steel nitrided (SSN) pin technologies.
There is a need in the art for more resistant timing chains for
gasoline direct injection and diesel engines.
SUMMARY OF THE INVENTION
[0003] An optimum steel composition for automotive chain link
plates has improved wear resistance. The composition is preferably
low alloy carbon steel with niobium and chromium.
[0004] In one embodiment, a steel composition includes, by weight
percentage, approximately 0.25-0.75% carbon, approximately
0.20-2.0% chromium, approximately 0.26-1.5% niobium, and the
remainder of the composition is iron and any impurities. This
composition may also optionally include one or more of the
following: approximately 0.2 to 1.0% manganese, approximately 0.05
to 0.60% silicon, up to approximately 0.30% aluminum, up to
approximately 0.03% phosphorus, or up to approximately 0.03%
sulfur.
[0005] In another embodiment, a steel composition includes, by
weight percentage, approximately 0.25 to 0.75% carbon,
approximately 0.2 to 1.0% manganese, approximately 0.05 to 0.60%
silicon, approximately 0.26-1.5% niobium, approximately 0.20 to
2.0% chromium, up to approximately 0.30% aluminum, up to
approximately 0.03% phosphorus, up to approximately 0.03% sulfur,
and a remainder of the composition being iron and any other
impurities.
[0006] The compositions described herein are preferably used for
automotive chain link plates. The chain links are preferably heat
treated to a hardness in the range of HRc 50 to 60, either by oil
quenching and tempering or salt bath austempring and/or
martempering preferably by salt bath austempering and/or
martempering.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 shows an example of a chain link/chain link plate
that could be made using the compositions described herein.
[0008] FIG. 2 shows an example of a silent chain including chain
links that could be made using the compositions described
herein.
[0009] FIG. 3A shows a top view of an example of a roller chain
that could be made using the compositions described herein.
[0010] FIG. 3B shows a side view of the roller chain of FIG.
3A.
[0011] FIG. 3C shows a section of the roller chain along line 3C-3C
of FIG. 3A.
[0012] FIG. 4A shows a top view of an example of a bushing chain
that could be made using the compositions described herein.
[0013] FIG. 4B shows a side view of the bushing chain of FIG.
4A.
[0014] FIG. 4C shows a section of the bushing chain along line
4C-4C of FIG. 4A.
DETAILED DESCRIPTION OF THE INVENTION
[0015] An optimum steel composition for automotive chain link
plates has improved wear resistance. The composition is preferably
Nb Cr low alloy carbon steel. The chain link plates made with the
compositions are preferably used in silent chains, roller chains or
bushing chains.
[0016] In one preferred embodiment, the steel composition includes
niobium, chromium, carbon, iron, and any impurities. One preferred
composition including these components includes, by weight
percentage, approximately 0.25%-0.75% carbon, approximately
0.20%-2.0% chromium, approximately 0.26%-1.5% niobium, and the
remaining component of the composition is iron. The amount of iron
in the composition is the remainder of the weight percentage of the
composition not made of other components in the composition. Trace
amounts of impurities may also be present.
[0017] The composition may also include one or more of the
following additional components (by weight percentage):
approximately 0.2%-2.0% manganese, approximately 0.05%-0.60%
silicon, up to approximately 0.30% aluminum, up to approximately
0.03% phosphorus, and up to approximately 0.03% sulfur. The amount
of iron in the composition is the remainder of the weight
percentage of the composition not made of other components in the
composition.
[0018] The chain link plates made using this steel composition are
preferably heat treated to a hardness in the range of HRc 50 to 60.
In some embodiments, heat treatment occurs either by oil quenching
and tempering or salt bath austempring and/or martempering
preferably by salt bath austempering and/or martempering. In some
embodiments, the hardness is in the range of HRc 52 to 58.
[0019] In one preferred embodiment, the composition includes the
following percentages (wt %) of materials:
TABLE-US-00001 C Mn Si Nb Cr Al P S 0.25-0.75% 0.2-1.0% 0.05-0.60%
0.26-1.5% 0.20-2.0% 0.30% 0.03% 0.03% max max max
[0020] The percentages of aluminum, phosphorus, and sulfur are
preferably maximum amounts of each of these materials. Phosphorus
and sulfur are impurities in steel and are preferred to be zero or
as close to zero as possible. Aluminum is also an impurity, and
should be kept as low as possible except in special applications.
The remainder of the steel composition is composed of iron and any
other impurities.
[0021] Steel compositions always have impurities and inclusions
including, but not limited to, Sulfides (MnS), Alumina, and
Silicate. There are industry standards to evaluate the inclusions.
One of the most common is ASTM E45. This standard or other industry
standards are used to control the amount of the impurities to an
acceptable level.
[0022] The amount of iron in the composition is the remainder of
the weight percentage of the composition not made of other
components in the composition. The chain link plates of this steel
composition are heat treated to a hardness of HRc 50-60. In some
preferred embodiments, heat treatment uses either oil quenching and
tempering or salt bath austempering and/or martempering by salt
bath. In some embodiments, the hardness is in the range of HRc 52
to 58.
[0023] The steel composition for the chain links described herein
fill the gap to further improve the wear resistance of the chains.
The composition includes carbon, niobium, chromium, and iron. The
steel of the composition preferably has a range of carbon from
0.25% to 0.75 wt %, which makes the steel hardenable after heat
treatment. In some preferred embodiments, the carbon weight
percentage ranges from 0.5-0.6%.
[0024] The composition also preferably includes a range of chromium
from 0.2%-2.0 wt %, which improves the hardenability of the steel
and makes the steel suitable for either oil quenching and tempering
or austempering and martempering as hardening options. In some
preferred embodiments, the chromium weight percentage ranges from
0.4%-0.6%.
[0025] The composition also preferably includes a weight percentage
of niobium in the range of 0.26% to 1.5 wt %. In some preferred
embodiments, the niobium content, by weight percentage, is between
approximately 0.26% and 0.8%. In other embodiments, the niobium
weight percentage in the composition is between 0.5% and 1.5%. In
other embodiments, the niobium content, by weight percentage, is
between 0.5% and 0.8%.
[0026] The niobium content in the steel composition not only
inhibits the grain growth of the steel and results in a fine
grained high strength steel, the niobium also forms nanoscale
Niobium Carbide particles after heat treatment. Increased Niobium
content results in more Niobium Carbide precipitation, with proper
heat treatment. These particles are particularly prevalent if an
austempering or martempering process is used for heat treatment,
because of the limited solubility of niobium in steel (1.5% max in
austerilized iron) and the reduced solubility with reductions of
temperature during heat treatment. When the carbides distribute
uniformly in the steel matrix in sub-micrometer and nanometer scale
particles, the wear resistance of the steel increases greatly
without negative impact on its fatigue properties, which are highly
desired for the silent chain links. As a result, the wear
resistance of the link plates are significantly improved.
[0027] The composition may also include one or more of the
following additional components (by weight percentage):
approximately 0.2%-2.0% manganese, approximately 0.05%-0.60%
silicon, up to approximately 0.30% aluminum, up to approximately
0.03% phosphorus, and up to approximately 0.03% sulfur. The amount
of iron in the composition is the remainder of the weight
percentage of the composition not made of other components in the
composition.
[0028] In one preferred embodiment, the composition includes the
following percentages (wt %) of materials:
TABLE-US-00002 C Mn Si Nb Cr Al P S 0.25-0.75% 0.2-1.0% 0.05-0.60%
0.26-1.5% 0.20-2.0% 0.30% 0.03% 0.03% max max max
[0029] In some of these embodiments, the carbon weight percentage
ranges from 0.5%-0.6%, the chromium weight percentage ranges from
0.4%-0.6%, and/or the niobium content, by weight percentage, ranges
from 0.26% and 0.8%. In other embodiments, the niobium content, by
weight percentage, is greater than 0.5%. In other embodiments, the
niobium content, by weight percentage, is between 0.5% and 0.8%.
The amount of iron in the composition is the remainder of the
weight percentage of the composition not made of other components
in the composition.
[0030] FIG. 1 shows an example of a chain link plate 1 that can be
made using the compositions described herein. FIG. 2 shows an
example of a silent chain 10 including chain links 1 made using the
compositions described herein. The chain includes guide or outside
links A and inside links B, as well as pins 2. Any component of the
silent chain 10 may be made of the compositions described
herein.
[0031] FIGS. 3A-3C show an example of a roller chain 20 with
bushings 35 that can be made using the compositions described
herein. The roller chain 20 includes guide links 30, bushing links
31, rollers 32, pins, 33, 34 and bushings 35. Any component of the
roller chain 20 may be made of the compositions described
herein.
[0032] FIGS. 4A-4C show an example of a bushing chain 25 with
bushings 45 that can be made using the compositions described
herein. The bushing chain 25 includes guide links 40, bushing links
41, pins 43, and bushings 45. Any component of the bushing chain 25
may be made of the compositions described herein.
[0033] In preferred embodiments, the compositions described herein
are used to make silent chain inside links B, which articulate with
the pins 2 and have issues with wear. While it is not necessary to
also use the steel compositions described herein for the guide
links A, the compositions may also be used for the guide links
A.
[0034] In other embodiments, the compositions described herein are
used to make bushings 35, 45 in a roller chain 20 or a bushing
chain 25. The compositions may also or alternatively be used to
make the links 30, 31, 40, 41, the rollers 32, and/or other
components of these types of chains.
[0035] The chain link plates made using the steel compositions
described herein are preferably heat treated to a hardness in the
range of HRc 50 to 60. In some embodiments, the composition is heat
treated either by oil quenching and tempering or salt bath
austempring and/or martempering preferably by salt bath
austempering and/or martempering. In some embodiments, the hardness
of the chain link plates is in the range of HRc 52 to 58.
[0036] In some embodiments, chain link plates made with the
composition described herein are used in combination with advanced
pin technologies including, but not limited to, VC pins or SSN
pins.
[0037] In some embodiments, the composition does not include
tungsten (W). In some embodiments, the composition does not include
any molybdenum (Mo). In some embodiments, the composition does not
include titanium (Ti), Nickel (Ni), and/or boron (B).
[0038] The chain link plate compositions described herein create a
more wear resistant chain. Due to the improved wear resistance of
the steel compositions described herein, it is unnecessary to coat
the chain link plates made with the compositions. This eliminates
both the cost and time associated with expensive coating
processes.
[0039] Accordingly, it is to be understood that the embodiments of
the invention herein described are merely illustrative of the
application of the principles of the invention. Reference herein to
details of the illustrated embodiments is not intended to limit the
scope of the claims, which themselves recite those features
regarded as essential to the invention.
* * * * *