JPS5970744A - High-hardness ni alloy for valve and valve seat for engine - Google Patents

Abstract

PURPOSE:To improve the hardness of the resulting titled alloy at high temp. as well as the resistance to thermal shock and corrosion due to lead oxide, by providing a specified composition consisting of C, Cr, Fe, W, Mo, Ti, Al and the balance essentially Ni. CONSTITUTION:This high-hardness Ni alloy for a valve and a valve seat for an engine has a composition consisting of, by weight, >2.0-3.5% C, 10-<28% Cr, 1-30% Fe, 0.1-17.0% W, 0.1-8.0% Mo, 0.01-4.5% Ti, 0.01-4.5% Al and the balance Ni with inevitable impurities. To the composition may be added one or more among 0.1-3.0% Si, 0.1-2.0% Mn, 0.01-1.5% Nb and 0.001-1.5% B as components for improving the performance.

Description

[Detailed description of the invention] This invention has excellent high temperature hardness and thermal shock resistance.

A Ni-based alloy with cylindrical hardness that has lead and lead oxide corrosion resistance and is suitable for use in castings or overlay welding in the production of engine valves and valve seats for internal combustion engines that particularly require these characteristics. It is related to.

Conventionally, when manufacturing engine valves and valve seats for internal combustion engines, the American Welding Association standard 5.13RCoCr-A (C: 0.9 to 1.4%) was used for overlay welding.

Si: 2.04 or less, Mn: 1.0% or less, W
:3.0~6.0'ly, Cr: 26~32%, Ni
:3. O% or less, Fe: 3.0 or less, Mo: 1.0
Co and unavoidable impurities (remaining) and 5.
13 ROoCr -B (C: 1.2-1.7%, Si: 2.0% or less, Mn: 1.(]% or less, W: 7.0-9.5 g, Or: 26-32%
, Ni: 3.0% or less, Fe: 3.0% or less, Mo: 1.0% or less, Go and unavoidable impurities: remaining 1 or more. It has been used a lot.

On the other hand, in recent years, as the performance of internal combustion engines has been improved, the engine valves of internal combustion engines and the same valve /-1 are required to have even better characteristics. In particular, when madder hardness is required, high-temperature hardness with a Vickers hardness of 320 or more at a temperature of 800°C, and a temperature of near 00°C [after holding for 15 minutes] , Thermal shock resistance where the water cooling operation is repeated 5 times or more before cracking occurs in the overlay weld, and temperature: 920
It is required that the lead oxide corrosion resistance has a weight loss of 0.09 f//Cfl/hr or less after being immersed for 1 hour in a molten oxidation vessel heated to 0.9°C [7z]. It goes without saying that engine valve castings and valve seat castings for internal combustion engines manufactured by casting are similarly required to have these characteristics.

However, the above-mentioned conventional CO-based alloys do not satisfy the above requirements in terms of high-temperature hardness, and also in terms of iJ thermal shock resistance and lead oxide corrosion resistance. When the above-mentioned conventional CO-based alloy is used for overlay welding and for casting in the production of engine valves and valve seats for high-performance engines that do not have properties that add to i and therefore require particularly high hardness. The current situation is that these products do not exhibit a fully satisfactory service life.

Therefore, from the above-mentioned viewpoint, the present inventors have developed a material that has the high-temperature hardness, thermal shock resistance, and lead oxide corrosion resistance required for engine valves and valve seats for internal combustion engines, particularly high-performance engines. As a result of research to develop a coating material that can be used for overlay welding and casting, we found that C: over 20% to 3.5%, Cr: 10 to 2
Less than 8%, Fe: 1-30, W: 0.1-17.0
Mo: 0.1 to 8.0.

Ti: 0.01-4.5, AM: 0.01-4
．． 5 and further contains Si: 0.1 as necessary.
~3.0%, Mn: 0.1-2.0 cycles, Nb:
0.01 to 1.5, and B.

A Ni-based alloy containing one or more of 1 to 1.5% of 0,0 O, with the remainder consisting of N1 and unavoidable impurities (by weight) has a Vickers alloy at a temperature of 800°C. Hardness: Extremely high high temperature hardness of 326 or higher, and in a thermal shock test where one cycle is heating to near 00℃ for 15 minutes and then water cooling, the number of cycles until cracking occurs is 8 or more. In addition, a lead oxide corrosion test conducted by immersion in a molten oxidation vessel heated to 920°C for 1 hour resulted in a weight loss of 0.031°C.
/cnl/hr It exhibits excellent lead oxide corrosiveness and can be used for overlay welding and casting. They obtained the knowledge that when used in the manufacture of the same valve seat, it exhibits excellent performance over an extremely long period of time.

This invention was made based on the above-mentioned knowledge, and the reason why the entire component composition was limited as described above will be explained below.

(a)c The C component includes Or, W, Mo, 'r4. ．．
It combines with Nb and Nb to form carbides, which has the effect of significantly improving the hardness at room temperature and 75 temperature. However, if the content is less than 20 parts, it is difficult to ensure particularly high high temperature hardness. On the other hand, if the content exceeds 3.5% K, the thermal shock resistance will deteriorate rapidly.
The content was determined to be more than 2.0 to 3.5 eI).

(b) In the Or Cr component, a part of it dissolves in solid solution in the base material, and the remaining part forms carbide, which particularly improves high-temperature hardness, improves high-temperature wear resistance, and improves oxidation resistance. It has the effect of improving lead corrosion resistance, but if its content is less than the T0 coefficient, the desired effect cannot be obtained, and if it is contained more than -28 width, there is a tendency for surface 1 thermal shock resistance to decrease. Therefore, the content was determined to be less than 10 to 28 parts.

(c) Fe The Fe component has the effect of further improving the thermal shock resistance of the alloy, but if its content is less than 1%, the desired 111i
l Thermal shock resistance could not be ensured, while 30qI)'
If the content exceeds 1 to 1, the high temperature hardness decreases, and it is difficult to ensure a Vickers hardness of 1320 or more at a temperature of 2800°C.
It was decided that there would be 30 people in charge.

(a,) The V/W component not only refines the carbide, but also forms carbide itself and dissolves in the matrix to strengthen it, thereby improving the high-temperature hardness and high-temperature strength of the alloy. However, if the content is less than 0.1%, the desired effect cannot be obtained, and on the other hand, if the content exceeds 17.0% (z), overlay weldability and machinability will deteriorate. Therefore, the content was determined to be between 0.1 and 17.0.

(e) M.

The 1φO component, in coexistence with V/, has the effect of forming a solid solution in the base material, strengthening it, and forming carbides to improve the high temperature hardness, high temperature wear resistance) and high temperature strength of the alloy. , its content is less than 0.1% iJ: 1'l
i The desired effect was not obtained in the above action, while 8.0% v
If the content exceeds , the thermal shock resistance and toughness will deteriorate.
It was set as Section 8.0.

(f) The Ti゛r] component not only suppresses the growth of crystal grains in the substrate, but also makes the crystal grains finer and forms MO-type carbides and nitrides, as well as Ni3 by combining with N1 and Al.
(/V!, Ti) has the effect of improving high-temperature hardness and thermal shock resistance, as well as high-temperature strength and toughness, but if its content is less than 0.01%, the above effects are impaired. The desired effect was not obtained, while 4.5%
'! If the content exceeds r, the amount of carbides will be too large and the thermal shock resistance and toughness will deteriorate, and the lead oxide corrosion resistance will also tend to deteriorate. It was set at 0.01 to 4.5%.

←) The AQ AM component contains Cr to improve lead oxide corrosion resistance.
And as mentioned above, it combines with N1 and T1 to form Ni3(A
In addition to forming intermetallic compounds (y, Ti), it also forms nitrides to improve hardness at room and high temperatures, further increasing wear resistance, and further improving thermal shock resistance and high temperature strength. If the content is less than 0.01%, the desired effect cannot be obtained, while if the content exceeds 4.5%, not only will the fluidity and castability of the molten metal decrease, Since the weldability and toughness also decrease and it becomes impractical, its content fI::o, o i
- 4.5 section.

(h) s i The S1 component has the effect of improving castability, build-up weldability, and sludge resistance, so it may be included as necessary when these properties are particularly required. , its content is 0
．． If the ratio is less than 1, the desired effect of improving the above action cannot be obtained;
On the other hand, even if 30% of In is added, no further improvement effect can be expected. :0.1～
It was designated as Section 3.0.

Since the S1 component has a deoxidizing effect, it is often used as a deoxidizing agent, and in this case it is contained as an unavoidable impurity in a range of less than 0.1%, but as an alloy component. 11, and this unavoidable impurity content may be included in the content, and the total ratio may be 0.1 or more.

(i) Mn Since the Mn component has the effect of improving overlay weldability,
In particular, it is contained as necessary when overlay weldability is required, but if the content is less than 0.1, the desired improvement effect on overlay weldability cannot be obtained; Even if the content exceeds that amount, no further improvement effect will be obtained, so the total content was set at 0.1 to 2.0%.

Since the shredded Mn component has a deoxidizing and desulfurizing effect, it is often used as a deoxidizing and desulfurizing agent, and in this case, like the S1 component, it is an unavoidable impurity in the range of 0.1/+5'j. However, the total content as an alloy component, including the unavoidable impurity content, should be 0.14 or more.

(j) rq 1) The +vb component has the effect of suppressing the growth of crystal grains in the base material, and forming MC-type carbides and nitrides to further improve high-temperature hardness and high-temperature wear resistance) and high-temperature strength. O,() i is included as necessary when high temperature hardness is required, but if the content is less than 4, the desired effect of improving the above action cannot be obtained;
If the content exceeds 0.01 to 1.5, lead oxide corrosion resistance and thermal shock resistance will deteriorate, and toughness will also decrease.

(k)B B component includes high temperature hardness, high temperature wear resistance), thermal shock resistance,
-Lead monoxide has the effect of further improving corrosivity and high-temperature strength, so it is included as necessary, but if the content is less than 0.0014, the desired effect of improving the above effects cannot be obtained; If the content exceeds 1.5%, the thermal shock resistance will decrease, and the castability and weldability will also deteriorate, so the content should be reduced to 0.00%.
It was set at 1 to 1.5%.

Next, the N1-based alloy of the present invention will be explained in detail by comparing examples and comparative examples.

Examples Ni-based alloys 1 to 38 of the present invention having the compositions shown in Table 1 were prepared by a conventional melting method. Ratio 1 bite N1 base alloy 1-12. A conventional alloy 1.2 having a composition corresponding to the conventional Co-based alloy mentioned above was completely melted and then continuously cast under normal conditions to a diameter of 4.8 m.
A welded rod of mφ was molded.

Comparative N1-based alloys 1 to 12 all have compositions in which the content of one of the constituent components (those marked with * in Table 1) is outside the scope of this invention. .

Next, the resulting Ni-based alloys of the present invention 1 to 38,
Comparative N1-based alloys 1 to 12. Using a conventional alloy 1°2 welding rod, diameter: 120m using a TIG automatic welding machine.
On the surface of the stainless steel (5US316) base metal with dimensions of mφ x thickness: 20 tnm, outer diameter: 100+
+onX width: 20mmX thickness = 5 brain circular beads 2
Layer overlay welding was performed.

Subsequently, the Rockwell hardness (C scale) at room temperature and the Vickers hardness at a temperature of 800°C were measured for the annular bead formed on the base metal, and the hardness of the annular bead formed on the base metal was measured. Then, a 1n11 thermal shock test was conducted in which the operation of heating to near 00°C, holding for 15 minutes, and then cooling with water was repeated as one cycle, and the number of cycles until cracking occurred in the annular bead was measured. I did it. Furthermore, diameter: I5wφ
× Length: Stainless steel piece with dimensions of 100 carp (5U
Two-layer overlay welding with a thickness of 5 + nm was performed on one end face of S316), and 1% directly from the overlay part of this copper piece:
1.2 mm φ
Molten lead oxide heated to 0°C: 1 hour immersion in 40g
Conducted a lead monoxide corrosion test, and removed the built-up part after the test.
A decrease of 1 was measured. These measurement results are also shown in Table 1.

From the results shown in Table 1, the Ni-based alloys 1 to 38 of the present invention
It is clear that all of these alloys have better cylinder temperature hardness, thermal shock resistance, and lead oxide corrosion resistance than conventional alloy 1.2. On the other hand, comparative Ni-based alloys 1~
As seen in 12, if the content of any of the constituent components falls outside the scope of the present invention, at least one of the +'r:i characteristics It is clear that one of the characteristics will be inferior.

In the above embodiments, the case where the N1-based alloy of the present invention was used for overlay welding was described.

Of course, even when this is used for casting, it exhibits excellent properties as in the case of overlay welding.

As mentioned above, the Ni-based alloy of the present invention has excellent high-temperature hardness and thermal shock resistance that satisfies the above-mentioned strict conditions required for engine valves and valve seats of high-performance engines with a margin of 7+:14. , and lead oxide corrosion resistance, so when used for overlay welding and casting in the manufacture of these parts, the resulting flakes will exhibit excellent performance over an extremely long period of time. be.

Applicant: Mitsubishi Metals Corporation

Claims (1)

[Claims] (1) C! :2. More than 0% to 3.5%, Or: 10
~Less than 28%, Fe: 1-30%, W: 0
．． 1-17.0%, M. : 0.1-8.0 section, Ti: 0.01-4.5 section, AA
1. A high hardness N1-based alloy for use in engine valves and valve seats of internal combustion engines, characterized by having a composition C or more (weight range) containing 0.01 to 4.51 i and the remainder consisting of N1 and unavoidable impurities. (2) O: more than 2.0% to 3.5%, Or: 10 to
Less than 28%, Fe: 1-30%, W: 0.1
~17.0%, M. 2 0.1~8.01 6. Ti: 0.01 to 4.
5%, A+! 20, 01-4.5 width,
and Si: Contains 0.1 to 3°0 and the remainder is N.
A high-hardness Ni-based alloy for engine nozzles and valve seats of internal combustion engines, characterized by having a composition (the above weight range) consisting of 1. 5%, Cr: 1
0 to less than 28%, Fe: 1 to 30%, W:
0.1~17.0'16. M. : 0.1~8.0%, Ti: 0.01~4.51
．． AQ: 0.01-4.5%, and Mn:
High hardness N1 for engine knobs and valve seats of internal combustion engines, characterized by having a composition [weight range above] containing 0.1 to 2.0% 'c gold, with the balance consisting of Ni and unavoidable impurities. Base alloy. (4) C: more than 2.0% to 3.5%, Or: 10 to
Less than 28%, Fe: 1-30%, W: 0
．． 1-17.0%, M. : 0.1~8.0 ratio, Ti: 0.01~4.5 ratio, Ag
: 0.01-4.5%, Si: 0.1-3.
0%, and Mn: 0.1 to 2.0%, with the remainder consisting of N1 and unavoidable impurities. Hardness N1 base alloy. (s) c:z, o<>3.5%, Cr: 1
0 to less than 28%, Fe: 1 to 30 <, W:
0.1-17.0%, M. : 0.1-8.0 section, Ti: 0.01-4.5 section, AA
: 0.01 to 45% total content, and further Nb: 0.0
1. A high-hardness N1-base alloy for use in engine valves and valve seats of internal combustion engines, characterized in that the alloy contains 1 to 1.5% F, with the balance consisting of Ni and unavoidable impurities (c or more weight %). (6) c: more than 2.0% to 3.5%, Or: l O
~28% uni,, 1t5. Fe: 1-30%, W
: 0.1-17.0%, M. :0.1~8.04. Ti: 0.01-4.5%,
Aff: 0.01-4.5%, and Si: 0.1-3
．． An engine valve for an internal combustion engine, characterized in that it further contains N1]: 0.01 to 1.5, and has a composition c or more, with the remainder consisting of Ni and unavoidable impurities. and high-hardness N1-based alloy for the same valve seat. (7) O: more than 2.0% to 3.5%, Or: 1
0~28% unfi%, Fe: 1~309f, W
: 0.1-17.0%, MO: 0.1-8.0,
Ti: 0.01~4.5, JV! : 0.01～
45%, and Mn: 0.1-2.0%'l:
For use in engine valves and valve seats of internal combustion engines, which further contain Nb: 0.01 to 1.5%, and have a composition (weight %) consisting of N1 and unavoidable impurities. High hardness N1 base alloy. (8)c:2. More than 0% ~ 3.5%, cr: 1o ~ 28%
less than, Fe: 1-30%, W: 0.1-17
．． 0%, M. : 0.1-8.0, Tf: 0.01-4.
5%, Mr. A: 0.01・~45%, Si
: 0.1-3.0%, and Mn: 0.1-2,0
An engine valve for an internal combustion engine, characterized in that it contains 0.01 to 1.5% cNb, and the remainder is Ni and unavoidable impurities (weight %). High hardness N1 base alloy for seats. (91C: more than 2.0% to 3.5%, LDr: 10
~28% not 2+? L Fe: 1-30%, W:
0.1-17.0%, M. : 0.1~8.0%, Ti: 0.01~4.5
%, Al4: 0.01 to 4.54 i, L/jcB: 0.001 to 1.5 ql), and the remainder is Ni and unavoidable impurities (wt%). A high hardness N1-based alloy for engine valves and valve seats of internal combustion engines, which is characterized by: (10) C: more than 2.0% to 3.5%, Or:
10 to less than 289f, Fe: 1 to 30%, W
: 0.1-17.0%. Mo: 0.1-80, Ti: 0.01-4.5
LI), AA: 0.01-4.5%, and Eii
: Contains 0.1 to 3.0 ratio, further B: 0.001 to
High hardness Ni for engine knobs and valve notes of internal combustion engines, characterized by having a composition (weight%) containing 1.5% and the remainder consisting of N1 and unavoidable impurities.
Base alloy. (II) C: 2. More than 0% to 3.5%, C
r: 1.0 to less than 28%, Fe: 1 to 30
%, W: 0.1-17.0%, M. : O01~8.0 ratio, Ti: 0.01~485 width, A
Q: 0.01-4. , 5%, and Mn:
Contains 0.1 to 2.0%, and further includes B: O, OO1
A high hardness Ni-based alloy for an engine nozzle and valve seat of an internal combustion engine, characterized in that it contains 1.5 qb and the balance 9 is Ni and unavoidable impurities (wt%): ff: (12) C: 2. Oqb >3.5%, Cr
: less than 10% to 28%, Fe: 1% to 30%, W
: 0.1-17.0%, M. 201-80, Ti,: 0.01-4.5, AH
: 0101~4.5%, Si: 0.1~3
．． 0%, and Mn: 0.1 to 2.01, further containing B: O, OO 1 to 1.5, and the remainder consisting of old and unavoidable impurities (weight %). A high hardness Ni-based alloy for engine valves and valve seats of internal combustion engines, characterized by: (13)c:2. oz >3.5%, Or:
Less than 10-28'%, Fe: 1-30%, W
: 0.1-17.0%, M. : 0.1~8.0%, Ti: '0.01~
4.5%, AA: 0.01-4.5%, further Nb: 0.01-1.5 eI) and B: 0. Contains OO1-1.5 and the remainder is Ni
A high hardness Ni-based alloy for use in engine valves and valve seats of internal combustion engines, characterized by having a composition (hereinafter referred to as "double band width") consisting of unavoidable impurities. (+410: over 2.0% to 3.5%, Car:
Less than 10-28'Iy, Fe: 1-30%,
W: 0.1-17.0%, M. :0.1~8.0%, Ti:0.01~4.5%, A
A: 0.01 to 4,5, and Si: 0.1
~3.0 ratio, further contains Nb: 0.01 to 1.5 ratio and B: 0.001 to 1,54 f, and the rest is N.
A high hardness Ni-based alloy for use in engine valves and valve seats of internal combustion engines, which is characterized by having a composition consisting of i and unavoidable impurities; (15) C: more than 2.0% to 3.5%, C
r: l (1 to less than 28%, Fe: 1 to 30%,
W: 0.1-17.0%, M. 20.1~80 section, 'ri:o, oi~4.5 section,
Ai! : 0.01~45%, and Mn: 0.1~
2. Contains O% f and further nb: 0.01 to 1.
5 eI) and B: O, OO 1 to 15 g, and the remainder is Ni and unavoidable impurities. High hardness N1 base alloy for valve seats. (+6) C: More than 2.0% to 3.5%, Or:
10~28% less l+i/i, Fe: 1~30
%, W: 0.1-17.0%, M. : 0.1-8.0 section, Tt: 0.01-4.5 section, AA
: 0.01-4.5%, Si: 0.1-3.
0%, and Mn: 0.1 to 20%,
Furthermore, Nl): 0.01 to 1.5 and B: 0.00
High hardness N for engine valves and valves of internal combustion engines, characterized by having a composition (weight ratio) containing 1 to 1.5% and the remainder consisting of N1 and unavoidable impurities.
i-base alloy.