U.S. patent application number 15/694345 was filed with the patent office on 2018-03-08 for cobalt-based cladding alloy for engine valve and engine.
This patent application is currently assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA. The applicant listed for this patent is TOYOTA JIDOSHA KABUSHIKI KAISHA. Invention is credited to Kimihiko ANDO, Yuki KAMO, Nobuyuki SHINOHARA.
Application Number | 20180066342 15/694345 |
Document ID | / |
Family ID | 59772464 |
Filed Date | 2018-03-08 |
United States Patent
Application |
20180066342 |
Kind Code |
A1 |
KAMO; Yuki ; et al. |
March 8, 2018 |
COBALT-BASED CLADDING ALLOY FOR ENGINE VALVE AND ENGINE
Abstract
A cobalt-based cladding alloy for an engine valve includes, by
mass %: Cr: 13% to 35%; Mo: 5% to 30%; Si: 0.1% to 3.0%; C: 0.04%
or less; Ni: 15% or less; W: 9% or less; Fe: 30% or less; Mn: 3% or
less; S: 0.4% or less; and Co and inevitable impurity elements as a
remainder. The amount of Co is 30% or more.
Inventors: |
KAMO; Yuki; (Okazaki-shi,
JP) ; ANDO; Kimihiko; (Toyota-shi, JP) ;
SHINOHARA; Nobuyuki; (Tajimi-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
Toyota-shi |
|
JP |
|
|
Assignee: |
TOYOTA JIDOSHA KABUSHIKI
KAISHA
Toyota-shi
JP
|
Family ID: |
59772464 |
Appl. No.: |
15/694345 |
Filed: |
September 1, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01L 2301/00 20200501;
C22C 19/07 20130101; F01L 2303/00 20200501; F01L 3/04 20130101;
C22C 30/00 20130101 |
International
Class: |
C22C 19/07 20060101
C22C019/07; C22C 30/00 20060101 C22C030/00; F01L 3/04 20060101
F01L003/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 8, 2016 |
JP |
2016-175665 |
Claims
1. A cobalt-based cladding alloy for an engine valve comprising, by
mass %: Cr: 13% to 35%; Mo: 5% to 30%; Si: 0.1% to 3.0%; C: 0.04%
or less; Ni: 15% or less; W: 9% or less; Fe: 30% or less; Mn: 3% or
less; S: 0.4% or less; and Co and inevitable impurity elements as a
remainder, wherein an amount of Co is 30% or more.
2. An engine comprising: an engine valve on which a cladding
material made of the cobalt-based cladding alloy according to claim
1 is deposited, wherein a fuel for the engine is any one of
ethanol, ethanol-blended gasoline, compressed natural gas, and
liquefied petroleum gas.
Description
INCORPORATION BY REFERENCE
[0001] The disclosure of Japanese Patent Application No.
2016-175665 filed on Sep. 8, 2016 including the specification,
drawings and abstract is incorporated herein by reference in its
entirety.
BACKGROUND
1. Technical Field
[0002] The present disclosure relates to a cobalt-based cladding
alloy for an engine valve, and an engine provided with an engine
valve on which a cladding material made of the cobalt-based
cladding alloy is deposited.
2. Description of Related Art
[0003] A cobalt-based cladding alloy excellent in corrosion
resistance and wear resistance is employed by a valve face of an
engine valve.
[0004] For example, Japanese Patent Application Publication No.
5-84592 (JP 5-84592 A) discloses a cobalt-based cladding alloy
consisting of, by parts by weight, Cr: 10% to 40%, Mo: more than
10% to 30%, W: 1% to 20%, Si: 0.5% to 5%, C: 0.05% to 3%, Al:
0.001% to 0.12%, 0: 0.001% to 0.1%, Fe: 30% or less, Ni: 20% or
less, Mn: 3% or less, and Co and inevitable impurity elements as
the remainder (here, the amount of Co is 30 wt % to 70 wt %).
SUMMARY
[0005] According to the cobalt-based cladding alloy described in JP
5-84592 A, since Fe is contained in an amount of 30% or less, the
toughness is improved, oxides are formed, and the effect as a
lubricant is exhibited. Cr, Mo, and W contained therein causes
solid solution strengthening of the Co-rich matrix, and by
regulating the O content by adding Al, the cladding properties can
be improved. In addition, since the valve face of the engine valve
operated under a high load is cladded, the wear resistance of the
engine valve is improved, and the low attackability is
simultaneously achieved, thereby achieving a cobalt-based cladding
alloy excellent in cladding properties.
[0006] However, for the purpose of reducing an environmental impact
load, ethanol, ethanol-blended gasoline, compressed natural gas
(CNG), liquefied petroleum gas (LPG) and the like are applied as
the fuel engine. A vehicle using ethanol and ethanol-blended
gasoline as the fuel is called a flexible-fuel vehicle (FFV).
[0007] When the ethanol-blended gasoline and the like are used, it
is possible to reduce the environmental impact load. However, a
severe corrosive environment or adhesive environment is formed
compared to gasoline of the related art, and thus there is concern
of excessive wear on a valve seat. Therefore, even with an engine
provided with an engine valve having the cobalt-based cladding
alloy described in JP 5-84592 A, that has excellent performance, it
is difficult for the engine to exhibit high corrosion resistance
and adhesion resistance compared to the case of using
ethanol-blended gasoline and the like.
[0008] The present disclosure provides a cobalt-based cladding
alloy for an engine valve capable of exhibiting high corrosion
resistance and adhesion resistance even in a case where
ethanol-blended gasoline or the like is used, and an engine
provided with an engine valve on which a cladding material made of
the cobalt-based cladding alloy is deposited.
[0009] According to a first aspect of the present disclosure, a
cobalt-based cladding alloy for an engine valve includes, by mass
%: Cr: 13% to 35%; Mo: 5% to 30%; Si: 0.1% to 3.0%; C: 0.04% or
less; Ni: 15% or less; W: 9% or less; Fe: 30% or less; Mn: 3% or
less; S: 0.4% or less; and Co and inevitable impurity elements as a
remainder (here, the amount of Co is 30% or more).
[0010] While the amount of C in the cobalt-based cladding alloy
described in JP 5-84592 A is 0.05 mass % to 3 mass %, the amount of
C in the cobalt-based cladding alloy for an engine valve according
to the aspect of the present disclosure is 0.04 mass % or less. In
this respect, the two sides are significantly different from each
other.
[0011] That is, since the amount of C in the cobalt-based cladding
alloy described in JP 5-84592 A is 0.05 mass % or more, hard
carbide phases are likely to be generated, and as the amount of the
carbide phases increases, there is a concern that the attackability
may increase. An excessive increase in the attackability of the
clad metal affects an increase in wear of the opponent valve
seat.
[0012] In addition, due to the generation of the carbides, the
amount of solid solutions of Cr and Mo decreases, and there is a
concern that the adhesion resistance or corrosion resistance may
decrease.
[0013] Contrary to this, since the amount of C in the cobalt-based
cladding alloy according to the aspect of the present disclosure is
0.04 mass % or less, the attackability can be reduced, and thus it
becomes possible to suppress wear of the opponent valve seat.
[0014] In addition, since the amount of C is small, the generation
of carbides is suppressed, and thus a reduction in the amount of
solid solutions of Cr and Mo is suppressed, resulting in a
cobalt-based cladding alloy provided with high corrosion resistance
and adhesion resistance.
[0015] As described above, the difference in the amount of C is
extremely important, and in a case where the above-mentioned
ethanol-blended gasoline or the like is used, the difference in
effect due to the difference in the amount of C becomes more
significant.
[0016] According to a second aspect of the present disclosure, an
engine includes: an engine valve on which a cladding material made
of the cobalt-based cladding alloy is deposited. A fuel for the
engine is any one of ethanol, ethanol-blended gasoline, compressed
natural gas (CNG), and liquefied petroleum gas (LPG).
[0017] Since the engine according to the second aspect of the
present disclosure is provided with the engine valve on which the
cladding material made of the cobalt-based cladding alloy in which
the amount of C is set to 0.04 mass % or less is deposited, wear of
the opponent valve seat of the engine valve is suppressed,
resulting in an engine having high durability.
[0018] As can be understood from the above description, according
to the cobalt-based cladding alloy for an engine valve according to
the second aspect of the present disclosure, since the amount of C
is set to 0.04 mass % or less, the attackability is reduced, and
the generation of hard carbides is suppressed. Therefore, a
cobalt-based cladding alloy provided with high corrosion resistance
and adhesion resistance can be obtained, and wear of the opponent
valve seat can be suppressed.
[0019] In addition, it is possible to provide an engine that is
highly durable even in a severe corrosive environment or adhesive
environment due to the use of ethanol, ethanol-blended gasoline,
CNG, LPG, or the like as a fuel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Features, advantages, and technical and industrial
significance of exemplary embodiments of the disclosure will be
described below with reference to the accompanying drawings, in
which like numerals denote like elements, and wherein:
[0021] FIG. 1 is a longitudinal sectional view of an engine valve
having a clad portion made of a cobalt-based cladding alloy
according to an embodiment of the present disclosure;
[0022] FIG. 2 is a view showing the results of a wear test, and is
a view particularly showing the relationship between the total wear
amount of the engine valve and a valve seat and the amount of C in
the cobalt-based cladding alloy;
[0023] FIG. 3 is an enlarged view of a range in which the amount of
C is 0 mass % to 0.05 mass % in FIG. 2; and
[0024] FIG. 4 is an SEM image of an example and a reference example
before and after a corrosion test.
DETAILED DESCRIPTION OF EMBODIMENTS
[0025] Hereinafter, an embodiment of a cobalt-based cladding alloy
for an engine valve according to an embodiment of the present
disclosure will be described with reference to the drawings.
Embodiment of Cobalt-Based Cladding Alloy for Engine Valve
[0026] FIG. 1 is a longitudinal sectional view of an engine valve
having a clad portion made of the cobalt-based cladding alloy
according to the embodiment of the present disclosure. As
illustrated in the figure, a clad portion 20 made of the
cobalt-based cladding alloy is annularly formed on the valve face
of an engine valve 10, and a valve seat (not illustrated) is
disposed on the opponent side on which the clad portion 20 abuts at
a high pressure when the engine valve 10 is mounted on a cylinder
head.
[0027] Here, the cobalt-based cladding alloy consists of, by mass
%: Cr: 13% to 35%; Mo: 5% to 30%; Si: 0.1% to 3.0%; C: 0.04% or
less; Ni: 15% or less; W: 9% or less; Fe: 30% or less; Mn: 3% or
less; S: 0.4% or less; and Co and inevitable impurity elements as
the remainder (here, the amount of Co is 30% or more).
[0028] Since an appropriate amount of Mo is added to the alloy that
forms a Cr passive film, regeneration of the Cr passive film can be
promoted. Therefore, even when the Cr passive film is broken due to
corrosion or sliding of the clad portion 20, the speed of the
regeneration of the Cr passive film by Cr and Mo exceeds the speed
of the breakage, resulting in a cobalt-based cladding alloy having
high corrosion resistance and adhesion resistance even in a
repeatedly sliding and highly corrosive environment.
[0029] The reasons for the numerical range of each metal element
will be described below in detail.
[0030] Cr: 13 Mass % to 35 Mass %
[0031] When Cr is in an amount of less than 13 mass %, a passive
oxide film is not formed and corrosion resistance is not exhibited.
Therefore, the lower limit of the amount of Cr is defined as 13
mass %. When the amount of Cr exceeds 35 mass %, the cladding
properties deteriorate. Therefore, the upper limit of the amount of
Cr is defined as 35 mass %.
[0032] Mo: 5 Mass % to 30 Mass %
[0033] When the amount of Mo is less than 5% by mass, the effect of
improving the corrosion resistance is insufficient. Therefore, the
lower limit of the amount of Mo is defined as 5 mass %. When the
amount of Mo exceeds 30 mass %, the cladding properties
deteriorate. Therefore, the upper limit of the amount of Mo is
defined as 30 mass %.
[0034] Si: 0.1 Mass % to 3.0 Mass %
[0035] When the amount of Si is less than 0.1 mass %, the cladding
properties (wettability) deteriorate. Therefore, the lower limit of
the amount of Si is defined as 0.1 mass %. When the amount of Si
exceeds 3.0 mass %, the attackability increases. Therefore, the
upper limit of the amount of Si is defined as 3.0 mass %.
[0036] C: 0.04 Mass % or Less
[0037] When the amount of C exceeds 0.04 mass %, the corrosion
resistance decreases and a eutectic structure having low corrosion
resistance is formed, resulting in corrosion. Therefore, the
attackability against the valve seat increases. In addition, the
amount of solid solutions of Cr and Mo decreases, resulting in a
decrease in the corrosion resistance. Therefore, the upper limit of
the amount of C is defined as 0.04 mass %.
[0038] Ni: 15 Mass % or Less
[0039] Ni is an element that contributes to the improvement in the
toughness and corrosion resistance of the clad metal. When the
amount of Ni exceeds 15 mass %, the wear resistance decreases, and
the cladding properties deteriorate. Therefore, the upper limit of
the amount of Ni is defined as 15 mass %.
[0040] W: 9 Mass % or Less
[0041] W is an element that contributes to the improvement in the
wear resistance of the clad metal. When the amount of W exceeds 9
mass %, the melting point rises and the cladding properties
deteriorates due to the rise of the melting point. Therefore, the
upper limit of the amount of W is defined as 9 mass %.
[0042] Fe: 30 Mass % or Less
[0043] Fe is an element that contributes to the improvement in the
toughness of the clad metal. When the amount of Fe exceeds 30 mass
%, the corrosion resistance decreases. Therefore, upper limit of
the amount of Fe is defined as 30 mass %.
[0044] Mn: 3 Mass % or Less
[0045] Mn is an element that contributes to the improvement in the
cladding properties. When the amount of Mn exceeds 3 mass %, the
wear resistance decreases. Therefore, the upper limit of the amount
of Mn is defined as 3 mass %.
[0046] S: 0.4 Mass % or Less
[0047] S is an element that contributes to the improvement in the
cladding properties (wettability) and a property that promotes
discharge of blowholes. When the amount of S exceeds 0.4 mass %,
solidification cracking occurs. Therefore, the upper limit of the
amount of S is defined as 0.4 mass %.
[0048] While the amount of C in the cobalt-based cladding alloy
described in JP 5-84592 A as above is 0.05 mass % to 3 mass %, the
amount of C in the cobalt-based cladding alloy for an engine valve
according to the embodiment of the present disclosure is 0.04 mass
% or less.
[0049] Since the amount of C in the cobalt-based cladding alloy
described in JP 5-84592 A is 0.05 mass % or more, hard carbide
phases are likely to be generated, and as the amount of the carbide
phases increases, the attackability tends to increase. An excessive
increase in the attackability of the clad metal affects an increase
in wear of the opponent valve seat. In addition, due to the
generation of the carbides, the amount of solid solutions of Cr and
Mo decreases, and the adhesion resistance or corrosion resistance
tends to decrease.
[0050] Contrary to this, since the amount of C in the cobalt-based
cladding alloy according to the embodiment of the present
disclosure is 0.04 mass % or less, the attackability can be
reduced, and thus it becomes possible to suppress wear of the
opponent valve seat. In addition, since the amount of C is small,
the generation of carbides is suppressed, and thus a reduction in
the amount of solid solutions of Cr and Mo is suppressed, resulting
in a cobalt-based cladding alloy provided with high corrosion
resistance and adhesion resistance.
[0051] As an engine provided with the engine valve 10 having the
clad portion 20, an engine to that any one of ethanol,
ethanol-blended gasoline, CNG, and LPG is applied as the fuel for
the engine is exemplified.
[0052] Since the engine is provided with the engine valve 10 having
the clad portion 20 on which the cladding material made of the
cobalt-based cladding alloy in which the amount of C is set to 0.04
mass % or less is deposited, wear of the opponent valve seat of the
engine valve 10 is suppressed even in a severe corrosive
environment or adhesive environment, and thus the engine has high
durability.
[0053] Experiments and Results Verifying Corrosion Resistance of
Engine Valve, Wear Resistance of Engine Valve and Valve Seat, and
the Like
[0054] The present inventors conducted experiments to verify the
corrosion resistance of the engine valve, the wear resistance of
the engine valve and the valve seat, and clad beads. Table 1 below
shows the composition of each of the cobalt-based cladding alloys
(Examples 1 to 11) according to the embodiment of the present
disclosure and cladding alloys of Comparative Examples 1 to 19.
Table 2 shows the experimental results regarding the corrosion
resistance, wear resistance, clad beads, and actual machine wear of
each of the cobalt-based cladding alloys. In addition, regarding
the results of a wear test, particularly the relationship between
the total wear amount of the engine valve and the valve seat and
the amount of C in the cobalt-based cladding alloy is shown in
Tables 3-1 and 3-2 below and FIGS. 2 and 3, and an SEM image of an
example and a reference example before and after a corrosion test
is shown in FIG. 4. Here, Reference Examples 1 and 2 in Tables 3-1
and 3-2 refer to the cobalt-based cladding alloy disclosed in JP
5-84592 A described above. In addition, the opponent valve seat of
the engine valve is a Fe-based valve seat, and is
Fe-16Mo-21Co-2.4Mn-1.1C (by mass %).
[0055] First, in an experiment regarding the corrosion resistance
of the engine valve, a test surface (mirror-polished surface) of a
specimen having planar dimensions of 20 mm.times.20 mm and a height
of 2 mm was immersed in an etchant at a pH of 2.0 for 24 hours, and
the cross section of the test surface was observed with SEM to
check the presence or absence of corrosion on the outermost layer
of the test surface.
[0056] In an experiment regarding the wear resistance, the valve
face of the engine valve is clad by a plasma cladding method
(output 130 A, processing speed 8 mm/sec), a single body wear test
was conducted, and by using an axial wear amount of 170 .mu.m as a
threshold, a wear amount of 170 .mu.m or more was evaluated as
impossible (X) in Tables 2 and 3-2.
[0057] Here, the summary of the single body wear test will be
described. This test is a test to investigate the attackability and
wear resistance of the cladding material. Specifically, a sliding
portion between a valve face that was clad and a valve seat made of
a Cu-based material and a Fe-based sintered material was subjected
to a propane gas combustion atmosphere using a propane gas burner
as a heating source. The wear test was conducted for 8 hours by
controlling the temperature of the valve seat to 200.degree. C.,
applying a load of 176 N when the valve face and the valve seat
were brought into contact with each other by a spring, and bringing
the valve face and the valve seat into contact with each other at a
rate of 2000 times/min. In this wear test, the depressed amount of
the valve from a reference position was measured. The depressed
amount of the valve corresponds to the wear amount (wear depth) to
that the engine valve and the valve seat were worn by contact.
[0058] In addition, in an experiment regarding the clad beads, it
was verified whether or not the cladding properties were poor and
whether or not cladding can be performed on the valve face. In
Tables 2, and 3-2, those on which cladding could be performed were
evaluated as possible (O), and those on which cladding could not be
performed were evaluated as impossible (X).
[0059] In addition, in an experiment regarding the actual machine
wear, an actual machine durability test was conducted for 300 hours
using a 2400 cc gasoline engine and an alcohol-containing fuel, and
in Tables 2 and 3-2, the limit reference value of the wear amount
(the total wear amount of the engine valve and the valve seat) is
shown as 100.
TABLE-US-00001 TABLE 1 Chemical composition (mass %) Co Cr Mo Ni W
Si C Fe Mn EXAMPLE 1 Remainder 21 12 6 3 0.8 0.01 5 0.3 EXAMPLE 2
Remainder 21 12 0 3 0.8 0.01 5 0.3 EXAMPLE 3 Remainder 21 12 0 0
0.8 0.01 5 0.3 EXAMPLE 4 Remainder 21 12 0 0 0.8 0.01 1 0.3 EXAMPLE
5 Remainder 13 5 0 0 0.8 0.01 1 0.3 EXAMPLE 6 Remainder 13 5 0 0
0.8 0.04 1 0.3 EXAMPLE 7 Remainder 21 5 0 0 0.8 0.01 1 0.3 EXAMPLE
8 Remainder 21 12 0 0 0.8 0.01 25 0.3 EXAMPLE 9 Remainder 21 12 6 3
0.8 0.04 5 0.3 EXAMPLE 10 Remainder 21 12 6 3 3.0 0.01 5 0.3
EXAMPLE 11 Remainder 21 12 6 3 0.8 0.01 0 3.0 COMPARATIVE EXAMPLE 1
Remainder 13 5 0 0 0.8 0.05 1 0.3 COMPARATIVE EXAMPLE 2 Remainder
21 12 6 3 0.8 0.05 5 0.3 COMPARATIVE EXAMPLE 3 Remainder 21 12 6 3
0.8 1.00 5 0.3 COMPARATIVE EXAMPLE 4 Remainder 21 12 0 0 0.8 0.05 0
0.3 COMPARATIVE EXAMPLE 5 Remainder 35 30 15 0 0.8 0.05 0 0.3
COMPARATIVE EXAMPLE 6 Remainder 35 30 0 0 0.8 0.04 0 0.3
COMPARATIVE EXAMPLE 7 Remainder 35 32 0 0 0.8 0.04 0 0.3
COMPARATIVE EXAMPLE 8 Remainder 21 12 6 10 0.8 0.01 0 0.3
COMPARATIVE EXAMPLE 9 Remainder 11 5 0 0 0.8 0.01 1 0.3 COMPARATIVE
EXAMPLE 10 Remainder 21 0 0 0 0.8 0.01 0 0.3 COMPARATIVE EXAMPLE 11
Remainder 35 30 15 10 0.8 0.01 0 0.3 COMPARATIVE EXAMPLE 12
Remainder 35 30 15 12 0.8 0.01 0 0.3 COMPARATIVE EXAMPLE 13
Remainder 21 12 0 0 0.8 0.01 30 0.3 COMPARATIVE EXAMPLE 14
Remainder 21 12 6 3 0.1 0.01 0 0.3 COMPARATIVE EXAMPLE 15 Remainder
21 12 6 3 3.5 0.01 0 0.3 COMPARATIVE EXAMPLE 16 Remainder 21 12 6 3
0.8 0.01 5 3.5 COMPARATIVE EXAMPLE 17 26 Remainder 27 -- -- 5 --
1.3 0.3 (Stellite 6) COMPARATIVE EXAMPLE 18 27 -- 21 -- 3.8 -- --
0.5 0.3 (SUH35) COMPARATIVE EXAMPLE 19 28 -- -- -- -- -- -- -- 0.3
(SUH35 nitriding)
TABLE-US-00002 TABLE 2 Wear resistance Axial wear amount (.mu.m)
Corrosion Engine Valve Total Clad Actual machine resistance
Determination valve seat amount beads wear EXAMPLE 1 .largecircle.
.largecircle. 4 29 33 .largecircle. 62 EXAMPLE 2 .largecircle.
.largecircle. 2 26 28 .largecircle. Not conducted EXAMPLE 3
.largecircle. .largecircle. 7 34 41 .largecircle. Not conducted
EXAMPLE 4 .largecircle. .largecircle. 10 50 60 .largecircle. Not
conducted EXAMPLE 5 .largecircle. .largecircle. 42 72 114
.largecircle. Not conducted EXAMPLE 6 .largecircle. .largecircle.
37 81 118 .largecircle. Not conducted EXAMPLE 7 .largecircle.
.largecircle. 50 80 130 .largecircle. Not conducted EXAMPLE 8
.largecircle. .largecircle. 13 34 47 .largecircle. Not conducted
EXAMPLE 9 .largecircle. .largecircle. 3 32 35 .largecircle. 97
EXAMPLE 10 .largecircle. .largecircle. 46 112 158 .largecircle. Not
conducted EXAMPLE 11 .largecircle. .largecircle. 10 158 168
.largecircle. Not conducted COMPARATIVE EXAMPLE 1 X .largecircle.
45 71 116 .largecircle. Not conducted COMPARATIVE EXAMPLE 2 X
.largecircle. 4 47 51 .largecircle. 100 or more COMPARATIVE EXAMPLE
3 X .largecircle. 2 55 57 .largecircle. 100 or more COMPARATIVE
EXAMPLE 4 X .largecircle. 5 45 50 .largecircle. Not conducted
COMPARATIVE EXAMPLE 5 X .largecircle. Not conducted X Not conducted
COMPARATIVE EXAMPLE 6 .largecircle. .largecircle. Not conducted X
Not conducted COMPARATIVE EXAMPLE 7 .largecircle. .largecircle. Not
conducted X Not conducted COMPARATIVE EXAMPLE 8 .largecircle.
.largecircle. Not conducted X Not conducted COMPARATIVE EXAMPLE 9 X
.largecircle. 40 66 104 .largecircle. Not conducted COMPARATIVE
EXAMPLE 10 X X 96 92 203 .largecircle. Not conducted COMPARATIVE
EXAMPLE 11 .largecircle. .largecircle. Not conducted X COMPARATIVE
EXAMPLE 12 Not Not Not conducted X conducted conducted COMPARATIVE
EXAMPLE 13 X .largecircle. 20 23 43 .largecircle. Not conducted
COMPARATIVE EXAMPLE 14 Not Not Not conducted X Not conducted
conducted conducted COMPARATIVE EXAMPLE 15 .largecircle. X 7 230
237 .largecircle. Not conducted COMPARATIVE EXAMPLE 16
.largecircle. X 50 130 180 .largecircle. Not conducted COMPARATIVE
EXAMPLE 17 X X 120 105 225 .largecircle. X (100 or more for
(Stellite 6) a time of 1/10) COMPARATIVE EXAMPLE 18 X X 130 111 241
-- Not conducted (SUH35) COMPARATIVE EXAMPLE 19 X .largecircle. 2
41 43 -- X (100 or more for (SUH35 nitriding) a time of 1/10)
TABLE-US-00003 TABLE 3-1 Chemical composition (mass %) Co Cr Mo Ni
W Si C Fe Mn EXAMPLE 1 Remainder 21 12 6 3 0.8 0.01 5 0.3 EXAMPLE
12 Remainder 21 12 6 3 0.8 0.03 5 0.3 EXAMPLE 9 Remainder 21 12 6 3
0.8 0.04 5 0.3 REFERENCE EXAMPLE 1 Remainder 21 12 6 3 0.8 0.05 1
0.3 REFERENCE EXAMPLE 2 Remainder 21 12 6 3 0.8 1.00 1 0.3
COMPARATIVE EXAMPLE 17 26 Remainder 27 -- -- 5 -- 1.3 0.3 (Stellite
6) COMPARATIVE EXAMPLE 19 28 -- -- -- -- -- -- -- 0.3 (SUH35
nitriding)
TABLE-US-00004 TABLE 3-2 Wear resistance Axial wear amount (.mu.m)
Corrosion Engine valve Total Clad Actual machine resistance
Determination valve seat amount beads wear EXAMPLE 1 .largecircle.
.largecircle. 4 29 33 .largecircle. 62 EXAMPLE 12 .largecircle.
.largecircle. 9 38 47 .largecircle. 70 EXAMPLE 9 .largecircle.
.largecircle. 3 32 35 .largecircle. 97 REFERENCE EXAMPLE 1 X
.largecircle. 6 37 43 .largecircle. 100 or more REFERENCE EXAMPLE 2
X .largecircle. 3 30 33 .largecircle. 100 or more COMPARATIVE
EXAMPLE 17 X X 120 105 225 .largecircle. X 100 or more for
(Stellite 6) a time of 1/10 COMPARATIVE EXAMPLE 19 X .largecircle.
2 41 43 .largecircle. X 100 or more for (SUH35 nitriding) a time of
1/10
TABLE-US-00005 TABLE 4-1 Chemical composition (mass %) Co Cr Mo Ni
W Si C Fe Mn S EXAMPLE 13 Remainder 21 12 6 3 0.8 0.01 5 0.3 0.1
EXAMPLE 14 Remainder 21 12 6 3 0.8 0.01 5 0.3 0.4 COMPAR- Remainder
21 12 6 3 0.8 0.01 5 0.3 0.5 ATIVE EXAMPLE 20
TABLE-US-00006 TABLE 4-2 Wear resistance Axial wear amount (.mu.m)
Corrosion Engine Valve Total Clad resistance Determination valve
seat amount beads EXAMPLE 13 .largecircle. .largecircle. 12 43 55
.largecircle. EXAMPLE 14 .largecircle. .largecircle. 13 41 54
.largecircle. COMPARATIVE Not conducted X (solidification EXAMPLE
20 cracking)
[0060] From Table 2, it could be seen that all of Examples 1 to 11
are excellent in corrosion resistance, wear resistance, and
cladding properties.
[0061] Regarding the actual machine wear, in any of Examples 1 and
9 as the experimental objects, the limit reference value of the
wear amount was less than 100, and good results are shown.
[0062] In contrast, in each of the comparative examples, any of
corrosion resistance, wear resistance, and cladding properties is
not satisfied. In any of Comparative Examples 2 and 3 as the
experimental objects of the actual machine wear experiment, the
result of the limit reference value of the wear amount is 100 or
more.
[0063] In addition, it can be seen from Tables 3-1 and 3-2 and
FIGS. 2 and 3, while the result of the limit reference value of the
wear amount is 100 or more in any of Reference Examples 1 and 2
(the cobalt-based cladding alloy disclosed in JP 5-84592 A) in
which the amount of C is 0.05 mass % or more, in any of Examples 1,
9, and 12 in which the amount of C is 0.04 mass % or less, the
limit reference value of the wear amount is lower than 100 and good
results are shown.
[0064] It can be seen from FIG. 4 that, in the SEM image before and
after the corrosion test, while hard phases are formed after the
corrosion test and corrosion is confirmed in Reference Example 2,
in Example 6, no corrosion is observed before and after the
corrosion test.
[0065] Furthermore, it can be seen from Tables 4-1 and 4-2 that
while any of Examples 13 and 14 in which the amount of C is 0.04
mass % or less and the amount of S is 0.4 mass % or less is
excellent in corrosion resistance, wear resistance, and cladding
properties, in Comparative Example 20 in which the amount of S is
0.5 mass % or more, solidification cracking occurs, and it is
confirmed that there is a problem in cladding properties.
[0066] While the embodiment of the present disclosure has been
described in detail with reference to the drawings, the specific
configurations are not limited to the embodiment, and design
changes and the like without departing from the gist of the present
disclosure are also included in the present disclosure.
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