JPH07316699A - Corrosion-resistant nitride-dispersed nickel base alloy having high hardness and strength - Google Patents

Abstract

PURPOSE:To produce a corrosion-resistant nitride-dispersed Ni base alloy having high hardness and strength. CONSTITUTION:This corrosion-resistant nitride-dispersed Ni base alloy having high hardness and strength contains, by weight, 15-35% Cr, 6-24% Mo, 1.0-8% Ta, 0.1-0.3% N and <=0.3% Si and further contains one or >=2 kinds among 0.5-6% Fe, 0.5-3% Mn, 0.001-0.1% B, 0.001-0.1% Zr, 0.001-0.01% Ca, 0.1-1% Nb, 0.1-4% W, 0.1-4% Cu and the balance Ni with inevitable impurities.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, for example, in manufacturing a conductor roll, which is a structural member of a continuous electroplating apparatus, hardness,
Since strength and corrosion resistance are required, Japanese Patent Publication No. 2-5
In addition to the corrosion-resistant Ni-based alloy as described in 7139, many other corrosion-resistant Ni-based alloys are used.

[0003]

However, in recent years, even in the industrial field where 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 spreading. Therefore, higher hardness, strength and corrosion resistance are required, but the above-mentioned conventional corrosion resistance N
No i-based alloy satisfies any one of the above-mentioned characteristics, and therefore, it is not possible to sufficiently cope with this.

[0004]

Therefore, the present inventors have
From the above viewpoints, as a result of research to develop a Ni-based alloy having high hardness and high strength, and also having excellent corrosion resistance, as a result, the Ni-based alloy was expressed as% by weight (hereinafter,% means% by weight). Indicated), Cr: 15 to 35%, Mo: 6 to 24%, T
a: 1.0 to 8%, N: 0.1 to 0.3%, Si: 0.
3% or less, further Fe: 0.5-6%, M
n: 0.5-3%, B: 0.001-0.1%, Zr:
0.001-0.1%, Ca: 0.001-0.01
%, Nb: 0.1 to 1%, W: 0.1 to 4% and C
u: a composition containing one or more of 0.1 to 4% and the balance Ni and inevitable impurities,
When a nitride having high hardness is finely dispersed and precipitated in the matrix by heat treatment, the resulting Ni-based alloy has high hardness and high strength due to the above-described dispersed and precipitated nitride. At the same time, it has been found that the precipitated nitride does not lower the corrosion resistance, so that it can be a corrosion-resistant Ni-based alloy having high hardness and high strength.

The present invention has been made on the basis of such findings, and Cr: 15 to 35%, Mo: 6 to 2
4%, Ta: 1.0 to 8%, N: 0.1 to 0.3%, S
i: 0.3% or less, further Fe: 0.5 to 6
%, Mn: 0.5 to 3%, B: 0.001 to 0.1%,
Zr: 0.001 to 0.1%, Ca: 0.001 to 0.
01%, Nb: 0.1 to 1%, W: 0.1 to 4% and C
u: characterized by being a corrosion-resistant nitride-dispersed Ni-based alloy containing one or more of 0.1 to 4% and the rest consisting of Ni and unavoidable impurities and having high hardness and strength. is there.

The reason why the composition of the Ni-based 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 15
If it is less than 0.1%, the desired effect cannot be obtained. On the other hand, if the content exceeds 35%, the strength is lowered. Therefore, the content is 15 to 35%, preferably 17 to 2%.
It was set to 2%.

(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 If the content exceeds 24%, the hot workability is remarkably reduced, so the content is set to 6 to 24%, preferably 19 to 21%.

(C) Ta The Ta component has a function of forming a solid passivation oxide film on the surface of the base material in a corrosive environment to form a solid passive oxide film in 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 desired action and effect cannot be obtained. On the other hand, if the content exceeds 8%, Since the hot workability is remarkably reduced, 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 less than 0.1%, the above
Effect is not obtained, while its content exceeds 0.3%.
As a result, coarse nitrides start to precipitate, and hot working
The content is 0.1 to 0.1%, since
It was set to 0.3%, preferably 0.11 to 0.2%.

(E) Si The Si component is indispensable for deoxidation of the molten metal, but if its content exceeds 0.3%, the hot workability is deteriorated, so its content is 0.3%. % Or less, preferably 0.1% or less.

(F) Fe, Mn, B, Zr and Ca Since these components have the effect of improving hot workability, they should be added if further excellent hot workability is required. , Its content is Fe: less than 0.5%,
When Mn: less than 0.5% and each of B, Zr and Ca: less than 0.001%, the above-mentioned desired effects cannot be obtained, while the content exceeds 6% in Fe and 3 in Mn. %, Each of B and Zr exceeds 0.1%, and Ca exceeds 0.01%, 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: 0.5 to 6% and Mn: 0.5 to 3%.
%, B: 0.001-0.1%, Zr: 0.001-
0.1%, Ca: 0.001-0.01%, desirably Fe: 0.6-4%, Mn: 0.6-1%, B: 0.0
02-0.08%, Zr: 0.002-0.08%, C
a: It was set to 0.002 to 0.008%.

(G) Nb, W and Cu These components have the effect of further improving the corrosion resistance, but their contents are Nb: less than 0.1%, W: less than 0.1% and Cu: 0. If it is less than 1%, the above-mentioned effects cannot be obtained. On the other hand, if the content of Nb exceeds 1%, the content of W exceeds 4%, and the content of Cu exceeds 4%, the workability is deteriorated, which is not preferable. Therefore, if the content of one or more elements selected from Nb, W and Cu is N
b: 0.1-1%, W: 0.1-4% and Cu: 0.1
.About.4%, preferably Nb: 0.2 to 0.5%, W: 0.
2-1% and Cu: 0.2-1%.

(H) Inevitable impurities Among the impurities, if C exceeds 0.1%, S exceeds 0.01%, and P exceeds 0.03%, the hot workability is significantly deteriorated. , Its content C: 0.1% or less,
S: 0.01% or less and P: 0.03% or less.

[0015]

EXAMPLES Next, the contents of the Ni-based alloy of the present invention will be specifically described based on Examples. Using an ordinary high-frequency melting furnace, an alloy melt having a predetermined composition was prepared in an Ar atmosphere and then cast into a mold, which had the composition shown in Tables 1 to 6 and a thickness of 8.5 mm. Is made,
This ingot is heated to a predetermined temperature in the range of 1000 to 1230 ° C., and while maintaining this temperature, first, hot rolling is performed once to reduce the thickness to 8.2 mm. Final thickness was set to 3 mm while reducing the thickness of 0.5 to 0.2 mm by rolling, and the presence or absence of cracks during rolling was observed. For those without cracks, a predetermined value within the range of 1220 to 1250 ° C. After holding for 1 hour at this temperature, water cooling, and subsequently heat treatment at a temperature in the range of 900 to 1100 ° C. for 30 minutes, to disperse and precipitate the nitride finely and uniformly in the base material. Invention Ni-based alloys 1-76,
Comparative Ni-based alloys 1 to 25 were produced.

Next, with respect to the Ni-based alloys 1 to 76 of the present invention and the comparative Ni-based alloys 1 to 25, the tensile strength was measured for the purpose of evaluating hardness or strength, and for the purpose of further evaluating corrosion resistance, 15 Using a test piece having dimensions of × 15 × 3 mm, 10% H ₂ SO ₄ boiling aqueous solution, 65% HNO
Corrosion tests were carried out by immersion in a ₃ boiling aqueous solution and a 3% HCl boiling aqueous solution for 24 hours, and the corrosion rate was calculated based on the results of this corrosion test. These results are shown in Tables 7-10.
It was shown to.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

[Table 5]

[0022]

[Table 6]

[0023]

[Table 7]

[0024]

[Table 8]

[0025]

[Table 9]

[0026]

[Table 10]

[0027]

From the results shown in Tables 7 to 10, the Ni-based alloys 1 to 76 of the present invention all have high hardness, high strength and excellent corrosion resistance, whereas the comparative Ni-based alloys 1 to 2
In No. 5, the content of any of the constituents is out of the range of the present invention (marked with * in Tables 5 to 6), and it is clear that at least one of the above characteristics is inferior. . As described above, since the Ni-based alloy of the present invention has high hardness and high strength and excellent corrosion resistance,
For example, in addition to conductor rolls, which are structural members of continuous electroplating equipment, chemical plants, flue gas desulfurization equipment such as boilers and structural equipment such as semiconductor equipment, food processing and medical instruments, and various blades exposed to seawater, etc. When applied as a hand tool member or the like, it exhibits excellent performance over a long period of time even in practical use under severe conditions.

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

Claims (3)

[Claims] 1. By weight%, Cr: 15 to 35%, Mo: 6 to 24%, Ta: 1.0
-8%, N: 0.1-0.3%, Si: 0.3% or less, further Fe: 0.5-6%, Mn: 0.5-3
%, B: 0.001-0.1%, Zr: 0.001-
Corrosion resistant nitriding having high hardness and high strength, characterized in that it contains one or more of 0.1% and Ca: 0.001 to 0.01%, and the rest is Ni and unavoidable impurities. Material-dispersed Ni-based alloy. 2. By weight%, Cr: 15-35%, Mo: 6-24%, Ta: 1.0
-8%, N: 0.1-0.3%, Si: 0.3% or less, Nb: 0.1-1%, W: 0.1-4%
And Cu: a corrosion-resistant nitride-dispersed Ni-based alloy having high hardness and high strength, characterized in that it contains one or more of 0.1 to 4% and the rest is Ni and inevitable impurities. . 3. By weight%, Cr: 15-35%, Mo: 6-24%, Ta: 1.0
-8%, N: 0.1-0.3%, Si: 0.3% or less, Fe: 0.5-6%, Mn: 0.5-3%, B: 0.0
01-0.1%, Zr: 0.001-0.1% and C
a: One or more of 0.001 to 0.01% are contained, and Nb: 0.1 to 1% and W: 0.1 to 0.1%.
4% and Cu: 0.1 to 4% of one or more of 0.1 to 4%, and the balance consisting of Ni and inevitable impurities, the corrosion resistant nitride-dispersed Ni having high hardness and strength. Base alloy.