JPH07316703A - Corrosion resisting nitride dispersion type nickel-base cast alloy having high wear resistance and high strength - Google Patents

Abstract

PURPOSE:To produce a corrosion resisting nitride dispersion type Ni-base cast alloy having high wear resistance and high strength. CONSTITUTION:This alloy is a corrosion resisting nitride dispersion type Ni-base cast alloy having high wear resistance and high strength. This Ni-base cast alloy has a composition consisting of, by weight, 17-35% Cr, 6-35% Mo, 1.0-8% Ta, >0.1-0.5% N, >0.3-5% Si, either or both of 0.1-5% Co and 0.1-0.5% V, and the balance Ni with inevitable impurities and further containing, if necessary, one or >=2 kinds among 0.01-6% Fe, 0.1-3% Mn, 0.001-0.1% B, 0.001-0.1% Zr, 0.001-0.1% Ca, 0.1-1% Nb, 0.1-4% W, and 0.1-4% Cu.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Ni-base cast alloy having high wear resistance and high strength and excellent corrosion resistance.

[0002]

2. Description of the Related Art Conventionally, for example, in a chemical / smelting plant or the like, under a sulfuric acid or hydrochloric acid, a stir bar or the like, which is a structural member of a slurry dissolving apparatus for ores, has been used for abrasion resistance, strength Since corrosion resistance is required, Japanese Patent Publication No. 2-57138
Starting with corrosion resistant Ni-based alloys such as those described in
Many other corrosion resistant Ni-based alloys are used.

[0003]

However, in recent years, in the industrial field in which the above-mentioned corrosion resistant Ni-based alloy is used, there is a strong demand for energy saving, and its use under more severe conditions is widespread. Are required to have higher wear resistance, strength and corrosion resistance, but the conventional corrosion-resistant Ni-based alloys described above do not satisfy any one of the above-mentioned characteristics. The current situation is that it cannot be done.

[0004]

Therefore, the present inventors have
From the above viewpoint, as a result of research to develop a Ni-based alloy having high wear resistance and high strength, and also having excellent corrosion resistance, as a result, the Ni-based alloy was weight% (hereinafter,% is weight %
Is shown), Cr: 17-35%, Mo: 6-35%,
Ta: 1.0-8%, N: over 0.1-0.5%, Si:
Over 0.3-5%, Co: 0: 1-5%, V:
One or two of 0.1 to 0.5% is contained, and if necessary, Fe: 0.01 to 6%, Mn: 0.
1-3%, B: 0.001-0.1%, Zr: 0.00
1 to 0.1%, Ca: 0.001 to 0.1%, Nb:
0.1 to 1%, W: 0.1 to 4% and Cu: 0.1
1% or more of 4% is contained, and the rest is Ni
And a composition consisting of unavoidable impurities and having a structure in which a nitride having a high hardness is finely dispersed and precipitated in the matrix by heat treatment, the resulting Ni-based alloy has
The dispersed and precipitated nitride has high wear resistance and high strength, and since the precipitated nitride does not deteriorate the corrosion resistance, it becomes a corrosion-resistant Ni-based casting alloy having high wear resistance and high strength. I got the knowledge that I would get it.

The present invention has been made on the basis of such findings, and Cr: 17 to 35%, Mo: 6 to 3
5%, Ta: 1.0 to 8%, N: over 0.1 to 0.5%,
Si: containing more than 0.3 to 5%, Co: 0: 1 to 5%,
V: contains one or two of 0.1 to 0.5%, and optionally Fe: 0.01 to 6%, M
n: 0.1-3%, B: 0.001-0.1%, Zr:
0.001-0.1%, Ca: 0.001-0.1%,
Nb: 0.1-1%, W: 0.1-4% and Cu:
Characterized by a corrosion-resistant nitride-dispersed Ni-based casting alloy containing one or more of 0.1 to 4% and the rest consisting of Ni and unavoidable impurities and having high wear resistance and high strength. Is.

The reason why the composition of the Ni-based cast alloy of the present invention is limited to the above range will be described.

(A) Cr The Cr component has the function of forming a solid solution in the matrix to improve the corrosion resistance and at the same time forming a finely dispersed nitride (Cr ₂ N) in the matrix to enhance the hardness and strength. This nitride does not reduce the corrosion resistance, but its content is 17
If the content is less than%, the above-mentioned desired effects cannot be obtained, while if the content exceeds 35%, the strength is reduced. Therefore, the content is 17 to 35%, preferably 17 to 25%.
Set to%.

(B) Mo Mo The Mo component has a function of forming a solid solution in the matrix to improve the corrosion resistance and strength, but if the content is less than 6%, the above-mentioned desired effects cannot be obtained, while When the content exceeds 35%, the fluidity of the molten metal is remarkably lowered, and casting defects are likely to occur. Therefore, the content is set to 6 to 35%, preferably 17 to 25%.

(C) Ta The Ta component has a function of forming a solid solution in the matrix and promoting the formation of a dense passive oxide film on the surface of the matrix under a corrosive environment to further improve the corrosion resistance. A substance (TaN) is formed to enhance hardness and strength, but if the content is less than 1.0%, the above-mentioned desired action and effect cannot be obtained, while if the content exceeds 8%. Since the fluidity of the molten metal decreases, its content is set to 1.0 to 8%, preferably 1.1 to 3.5%.

(D) N N component reacts with Cr and Ta when added in a certain amount or more.
And finely dispersed Cr ₂N and TaN phase nitrides
Formed to significantly improve the hardness and strength of the alloy.
However, if the content is 0.1% or less, the above
Effect is not obtained, while its content exceeds 0.5%.
As a result, coarse nitrides start to precipitate, and corrosion resistance is improved.
Since it is lowered, its content exceeds 0.1 to 0.5.
%, Preferably over 0.1 to 0.3%.

(E) Si The Si component is indispensable for deoxidation of the molten metal and has an effect of remarkably improving the fluidity of the molten metal, but the content thereof is 0.
When the content is 3% or less, the above-described desired effects cannot be obtained, and when the content exceeds 5%, the strength is lowered. Therefore, the content is more than 0.3 to 5%, preferably 0.5. ~
It was set to 2%.

(F) Co and V These components function as a solid solution in the base material to increase the hardness of the base material and improve the wear resistance, so that higher hardness and wear resistance are required. If contained,
When the content is Co: less than 0.1% and V: less than 0.1%, the above-mentioned effects cannot be obtained, while the content is C.
If the content of o exceeds 5% and the content of V exceeds 0.5%, the fluidity of the molten metal decreases, and casting defects easily occur. Therefore, the content of Co: 0.1 to 5%, V: 0.1-0.5%,
Desirably, Co: 0.5-4%, V: 0.2-0.4
It was set to 5%.

(G) Fe, Mn, B, Zr and Ca These components have the function of improving the strength as well as the flowability of the molten metal, so that further excellent fluidity of the molten metal is required. If necessary, the content is Fe: less than 0.01%, Mn:
Less than 0.1%, B: less than 0.001%, Zr: 0.00
If it is less than 1% and Ca: less than 0.001%, the above-mentioned effects cannot be obtained, while the content exceeds 6% in Fe,
If Mn exceeds 3% and B, Zr and Ca exceed 0.1% respectively, the corrosion resistance decreases, which is not preferable. Therefore, the content of one or more elements selected from Fe, Mn, B, Zr and Ca is Fe:
0.01-6%, Mn: 0.1-3%, B, Zr and C
a: 0.001 to 0.1%, preferably Fe:
0.05 to 4%, Mn: 0.2 to 2%, B, Zr and Ca: 0.002 to 0.08% respectively.

(H) Nb, W and Cu These components have the effect of further improving the corrosion resistance, but if the contents are Nb, W and Cu respectively: less than 0.1%, the above-mentioned desired effects are obtained. On the other hand, if the content of Nb exceeds 1% and the content of W and Cu exceeds 4% respectively, the fluidity of the molten metal deteriorates and casting defects occur, which is not preferable. Therefore, the content of one or more of the elements selected from Nb, W and Cu is
Nb: 0.1 to 1%, W: 0.1 to 4% and Cu: 0.
1 to 4%, preferably Nb: 0.2 to 0.5%, W:
0.2 to 1% and Cu: 0.2 to 1%.

(I) Inevitable Impurities Among the impurities, if the C content exceeds 0.1%, the S content exceeds 0.01%, and the P content exceeds 0.03%, the fluidity of the molten metal is deteriorated. The content was suppressed to C: 0.1% or less, S: 0.01% or less, and P: 0.03% or less.

[0016]

[Examples] Using an ordinary high-frequency melting furnace, an alloy melt having a predetermined composition was prepared in an Ar atmosphere and then cast in a mold to produce castings having the component compositions shown in Tables 1 to 4, 1150 to 1 for castings without significant casting defects
After performing a homogenization treatment at a predetermined temperature within a range of 230 ° C for 10 hours, a heat treatment is performed at a predetermined temperature within a range of 900 to 1100 ° C for a period of 30 minutes. Ni-based casting alloys 1 to 60 of the present invention and comparative Ni-based casting alloys 1 to 1 by finely and uniformly dispersing and depositing nitrides
14 was produced.

Next, for the purpose of evaluating the strength of the Ni-based cast alloys 1 to 60 of the present invention and the comparative Ni-based cast alloys 1 to 14 obtained as a result, the tensile strength and the wear resistance were evaluated. For the purpose of measuring Vickers hardness and further evaluating corrosion resistance, a test piece having a size of 15 × 15 × 3 mm was used, 10% H ₂ SO ₄ boiling aqueous solution, 65% H
Corrosion tests were performed by immersion in a boiling NO ₃ solution and a boiling 3% HCl solution for 24 hours, and the corrosion rate was calculated based on the results of the corrosion test. Table 5 shows these results.
7 shows.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

[Table 4]

[0022]

[Table 5]

[0023]

[Table 6]

[0024]

[Table 7]

[0025]

From the results shown in Tables 5 to 7, the present invention N
The i-based casting alloys 1 to 60 all have high wear resistance, high strength and excellent corrosion resistance, while the comparative Ni-based casting alloys 1 to 14 have a content of any one of the constituent components. , Which is outside the scope of the present invention (marked with * in Table 4), and it is clear that at least one of the above characteristics is inferior. As described above, the Ni of the present invention
Since the base casting alloy has high wear resistance and high strength, and excellent corrosion resistance, for example, in addition to conductor rolls, which are structural members of continuous electroplating equipment, flue gas desulfurization of chemical plants, boilers, etc. When applied as structural members such as devices and semiconductor devices, food processing and medical equipment, and various blades and hand tool members exposed to seawater, etc., they are excellent for a long time even when used under severe conditions. It demonstrates its performance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kouji Toyozou 1-297 Kitabukurocho, Omiya City, Saitama Prefecture Central Research Laboratory, Mitsubishi Materials Co., Ltd.

Claims (4)

[Claims] 1. By weight%, Cr: 17-35%, Mo: 6-35%, Ta: 1.0
-8%, N: more than 0.1-0.5%, Si: more than 0.3-5%, further Co: 0: 1-5%, V: 0.1-0.5%.
A corrosion-resistant nitride-dispersed Ni-based casting alloy having high wear resistance and high strength, characterized in that it contains one or two of the above and the balance consists of Ni and inevitable impurities. 2. By weight%, Cr: 17-35%, Mo: 6-35%, Ta: 1.0
-8%, N: more than 0.1-0.5%, Si: more than 0.3-5%, Co: 0: 1-5%, V: 0.1-0.5% Of 1
Or 2 kinds, further, Fe: 0.01 to 6%, Mn: 0.1 to 3%, B: 0.
001-0.1%, Zr: 0.001-0.1% and Ca: 0.001-
A corrosion-resistant nitride-dispersed Ni-based casting alloy having high wear resistance and high strength, characterized in that it contains one or more of 0.1% and the rest is Ni and inevitable impurities. 3. By weight%, Cr: 17-35%, Mo: 6-35%, Ta: 1.0
-8%, N: more than 0.1-0.5%, Si: more than 0.3-5%, Co: 0: 1-5%, V: 0.1-0.5% Of 1
Or 2 kinds, further Nb: 0.1 to 1%,
1 of W: 0.1 to 4% and Cu: 0.1 to 4%
A corrosion-resistant nitride-dispersed Ni-based casting alloy having high wear resistance and high strength, characterized in that it contains one or more kinds, and the rest is Ni and unavoidable impurities. 4. By weight%, Cr: 17-35%, Mo: 6-35%, Ta: 1.0
-8%, N: more than 0.1-0.5%, Si: more than 0.3-5%, Co: 0: 1-5%, V: 0.1-0.5% Of 1
Or 2 kinds, Fe: 0.01 to 6%, Mn: 0.1 to 3%, B: 0.
001-0.1%, Zr: 0.001-0.1% and Ca: 0.001-
One or more of 0.1% are contained, and Nb: 0.1 to 1%, W: 0.1 to 4% and Cu:
Corrosion resistant nitride-dispersed N having high wear resistance and high strength, characterized by containing one or more of 0.1 to 4%, and the balance consisting of Ni and unavoidable impurities.
i-base casting alloy.