JPH083665A - Nickel-base superalloy for die excellent in oxidation resistance and high temperature strength - Google Patents

Abstract

PURPOSE:To produce an Ni-base superalloy for a die excellent in oxidation resistance and high temp. strength. CONSTITUTION:This Ni-base superalloy for a die excellent in oxidation resistance and high temp. strength is the one having a compsn. contg., by weight, 0.8 to 7% Al, 0.8 to 7% Ti, 13 to 25% Mo, 8 to 16% Cr, 1.1 to 8% Ta, <=2.5% Si, <=3% Mn, 0.0001 to 0.1% N and <=0.1% C, furthemtore contg., at need, one or >= two kinds among 0.01 to 6% Fe, 0.001 to 0.1% B, 0.001 to 0.1% Zr, 0.001 to 0.01% Ca, 0.1 to 5% Co, 0.1 to 0.5% V, 0.1 to 4% W, 0.1 to 1% Nb, 0.1 to 2% Hf and 0.1 to 2% 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 super heat-resistant alloy for dies, and more specifically, it can be used for isothermal forging of super heat-resistant alloys forged in dies heated to a high temperature. Ni for dies with excellent oxidation resistance and high temperature strength
It relates to a base super heat-resistant alloy.

[0002]

2. Description of the Related Art Conventionally, for example, since a material for a die for forging used at high temperature is required to have oxidation resistance and high temperature strength, a Mo base alloy (TZ
M) and many Ni-based super heat resistant alloys having excellent oxidation resistance are used.

[0003]

However, in recent years, due to the strong demand of the industrial world, various super heat resistant materials have been developed, and for example, for mold materials used for forging these materials, However, it is required to be used under severer conditions such as higher temperature, and there is a demand for a super heat-resistant alloy for molds which is excellent in oxidation resistance and high temperature strength. However, since the Mo-based alloy (TZM) described above is inferior in oxidation resistance particularly at high temperatures, it is necessary to perform forging in a vacuum or an inert gas, which complicates the forging equipment and increases workability. Is bad,
Moreover, there was a problem that the equipment cost was high. In addition, the above-mentioned conventional Ni-base superalloys generally have good oxidation resistance at high temperatures, and thus can be used in the atmosphere, but at a temperature higher than 1000 ° C. Then,
In particular, the high temperature strength is often insufficient and the oxidation resistance may not be satisfied in some cases, so that it is the current situation that it is not possible to sufficiently meet the above demands.

[0004]

Therefore, the present inventors have
From the above viewpoint, a Ni-based super heat-resistant alloy that is a die material for forging that is excellent in oxidation resistance and high-temperature strength and that can be used at temperatures of 1000 to 1200 ° C. and in the atmosphere. As a result of conducting research to develop, a Ni-based super heat-resistant alloy, in% by weight (hereinafter,% means% by weight), Al: 0.8 to 7%, Ti: 0.8 to 7%,
Mo: 13-25%, Cr: 8-16%, Ta: 1.1
~ 8%, Si: 2.5% or less, Mn: 3% or less, N:
Contains 0.0001 to 0.1%, C: 0.1% or less,
Further, if necessary, Fe: 0.01 to 6%, B: 0.0
01-0.1%, Zr: 0.001-0.1%, Ca:
0.001-0.01%, Co: 0.1-5%, V:
0.1-0.5%, W: 0.1-4%, Nb: 0.1
1%, Hf: 0.1-2%, and Cu: 0.1-2%
If one or more of the above are contained and the rest is composed of Ni and unavoidable impurities, the resulting Ni-based alloy becomes a Ni-based superheat-resistant alloy for molds that is excellent in oxidation resistance and high-temperature strength. I got the knowledge that I would get it.

The present invention has been made on the basis of such knowledge, and Al: 0.8 to 7%, Ti: 0.8
~ 7%, Mo: 13-25%, Cr: 8-16%, T
a: 1.1 to 8%, Si: 2.5% or less, Mn: 3% or less, N: 0.0001 to 0.1%, C: 0.1% or less, and if necessary. , Fe: 0.01-6%,
B: 0.001-0.1%, Zr: 0.001-0.1
%, Ca: 0.001-0.01%, Co: 0.1-5
%, V: 0.1 to 0.5%, W: 0.1 to 4%, Nb:
0.1 to 1%, Hf: 0.1 to 2%, and Cu: 0.
Characterized by a Ni-based super heat-resistant alloy for a mold, which contains 1 or 2 or more of 1 to 2% and the balance is Ni and unavoidable impurities and is excellent in oxidation resistance and high temperature strength. Is.

The reason why the component composition of the Ni-base superalloy according to the present invention is limited to the above range will be described.

(A) Al and Ti Al and Ti components react with the base component to form Ni ₃
Forming Al and Ni ₃ Ti (γ ′ phase) has the effect of improving the high temperature strength of the base material, but if the content of Al or Ti is less than 0.8%, the above effect cannot be obtained,
On the other hand, if the content of Al or Ti exceeds 7%, the eutectic crystallizes out and deteriorates the forgeability. Therefore, the content is Al: 0.8-7%, Ti: 0.8-7%. Desirably, Al: 3 to 6.5% and Ti: 1 to 4% were set.

(B) Mo Mo The Mo component has a function of forming a solid solution in the base material to enhance the high temperature strength of the base material, but if the content thereof is less than 13%, the above-mentioned desired effects cannot be obtained. If the content exceeds 25%, the oxidation resistance decreases, so the content should be 1
It is set to 3 to 25%, preferably 15 to 20%.

(C) Cr The Cr component has an effect of improving the oxidation resistance, but if the content of Cr is less than 8%, the above-mentioned desired effects cannot be obtained, while the content of Cr is 16%. If it exceeds the above range, the ductility decreases, so the content is 8 to 16%, preferably 10%.
-14%.

(D) Ta The Ta component has the function of improving the high temperature oxidation resistance, but if the content is less than 1.1%, the above-mentioned effects cannot be obtained, while the content thereof is 8%. If it exceeds 1.0, the high temperature strength will decrease, so the content was set to 1.1 to 8%, preferably 1.1 to 3%.

(E) Si The Si component has the function of improving the oxidation resistance and the function of improving the forgeability by deoxidizing the molten metal.
If the content exceeds 2.5%, the toughness of the alloy decreases, so the content was set to 2.5% or less, preferably 0.3% or less.

(F) Mn The Mn component has a desulfurizing action and has an effect of improving high temperature strength, but if its content exceeds 3%, it is not preferable because the oxidation resistance is deteriorated. The amount was set to 3% or less, preferably 1%.

The (g) N N component has an action of improving ductility, but if the content thereof is less than 0.001%, the above-mentioned desired action and effect cannot be obtained, while the content thereof is 0. If it exceeds 0.1%, the toughness decreases, so the content is 0.0001-0.
It is set to 1%, preferably 0.001 to 0.05%.

(H) When the content of the C component as a C impurity exceeds 0.1%,
Since the amount of carbides existing in the grain boundaries is increased and the ductility and toughness of the alloy are deteriorated, the content thereof is set to 0.1% or less, preferably 0.02% or less.

(I) Fe, B, Zr and Ca Since these components have the effect of improving ductility and toughness, they are contained as necessary when more excellent ductility and toughness are required. The content is Fe: 0.0
Less than 1%, B: less than 0.001%, Zr: 0.001%
Less than Ca: less than 0.001%, the desired effects cannot be obtained, while the content of Fe exceeds 6%, and B
Over 0.1%, Zr over 0.1%, Ca over 0.1%.
If it exceeds 01%, the high temperature strength tends to decrease, so the content of Fe: 0.01 to 6%,
B: 0.001-0.1%, Zr: 0.001-0.1
%, Ca: 0.001-0.01% Desirably, Fe:
0.5-4%, B: 0.002-0.01%, Zr:
0.002-0.01%, Ca: 0.002-0.00
It was set at 8%.

(J) Co, V and W Since these components have the effect of improving the high temperature strength,
It is contained as needed when it is required to further increase the high temperature strength, but when the content is Co: less than 0.1%, V: less than 0.1%, W: less than 0.1%. , The desired effect described above cannot be obtained, while the content of Co is 5%.
%, V exceeds 0.5%, and W exceeds 4%, the ductility and toughness decrease, so the content is set to Co:
0.1-5%, V: 0.1-0.5%, W: 0.1-4
% Desirably Co: 0.2 to 2%, V: 0.2 to 0.4
%, W: 0.2 to 2%.

(K) Hb, Hf and Cu These components have the function of improving the high temperature oxidation resistance, so that they are contained as necessary when further excellent high temperature oxidation resistance is required. When the content is Nb: less than 0.1%, Hf: less than 0.1%, and Cu: less than 0.1%, the above-mentioned desired effects cannot be obtained, while the content is Nb.
When Hf exceeds 1%, Hf exceeds 2%, and Cu exceeds 2%, the high temperature strength tends to decrease.
The content is Nb: 0.1 to 1%, Hf: 0.1 to 2
%, Cu: 0.1 to 2%, preferably Nb: 0.2 to
It was set to 0.5%, Hf: 0.2 to 1%, and Cu: 0.2 to 1%. (L) Inevitable impurities Inevitable impurities such as S, P, Sn, Zn and Pb are unavoidable as the dissolution raw material.

[0018]

EXAMPLES Next, the contents of the Ni-base superalloy according to the present invention will be specifically described based on Examples. Using controlled atmosphere is a high frequency melting furnace capable, in particular for adding N to the alloy, the atmosphere during dissolution and a mixed gas atmosphere of Ar gas and N ₂ gas, the mixing ratio of the Ar gas and N ₂ gas and mixed The N addition amount was controlled by changing the gas pressure. After that, the molten metal is forged into a die to prepare an ingot having a composition shown in Tables 1 to 5 and a thickness of 8.5 mm, and the ingot is homogenized for 24 hours within a range of 1150 to 1230 ° C. After the treatment, it is heated to a predetermined temperature within the range of 1000 to 1230 ° C., and while being kept at this temperature, the thickness is reduced to 8.2 mm by the first hot rolling process. Final thickness was set to 3 mm while reducing the thickness of 0.2 to 0.5 mm by rolling, and the presence or absence of cracks was observed during rolling.
After holding for 1 hour at a predetermined temperature within the range of ~ 1250 ° C,
It was water-cooled, and subsequently heat-treated under the condition of being kept at a temperature in the range of 900 to 1100 ° C. for 30 minutes, and the present invention Ni-base superalloys 1 to 57 shown in Tables 1 to 5 and comparative Ni-base superalloy 1 ~ 15 were produced. Further, as a conventional alloy, an alloy having the composition shown in Table 5 was prepared separately.

Next, the above-mentioned Ni-base superalloys of the present invention 1 to
63, comparative Ni-base superalloys 1 to 15 and conventional alloys were subjected to a high temperature tensile test for the purpose of evaluating high temperature strength. Also, for the purpose of evaluating oxidation resistance, 1100 ° C
In the dry air, the forced air cooling was repeated for 12 cycles (100 hours in total), and an oxidation test was performed to measure the corrosion weight loss.
The results are shown in Tables 5-7.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Table 3]

[0023]

[Table 4]

[0024]

[Table 5]

[0025]

[Table 6]

[0026]

[Table 7]

[0027]

[Table 8]

[0028]

From the results shown in Tables 6-8, the Ni of the present invention
The base alloys 1 to 57 all have excellent oxidation resistance and high-temperature strength, while in the comparative Ni base alloys 1 to 15, the contents of the essential elements in the Ni base alloys constituting them are the same as those of the present invention. It is clear that when the value is out of the range, at least one of the characteristics of oxidation resistance and high temperature strength is inferior, and the conventional alloy Mo alloy (TZM) is inferior in high temperature strength in the atmosphere. Is clear. As described above, the Ni-based alloy of the present invention has further excellent oxidation resistance and high-temperature strength, and thus has high performance as a die material for forging used at high temperatures, and is very useful industrially. Is.

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

Claims (8)

[Claims] 1. By weight%, Al: 0.8 to 7%, Ti: 0.8 to 7%, Mo: 13
-25%, Cr: 8-16%, Ta: 1.1-8%, S
i: 2.5% or less, Mn: 3% or less, N: 0.0001
.About.0.1%, C: 0.1% or less, and the balance consisting of Ni and unavoidable impurities, a Ni-based super heat-resistant alloy for molds excellent in oxidation resistance and high temperature strength. 2. By weight%, Al: 0.8 to 7%, Ti: 0.8 to 7%, Mo: 13
-25%, Cr: 8-16%, Ta: 1.1-8%, S
i: 2.5% or less, Mn: 3% or less, N: 0.0001
To 0.1%, C: 0.1% or less, and further Fe: 0.01 to 6%, B: 0.001 to 0.1%, Z
r: 0.001-0.1%, Ca: 0.001-0.0
1% or more of 1%, and the rest is N
Ni-based super heat-resistant alloy for dies, which is composed of i and unavoidable impurities and is excellent in oxidation resistance and high-temperature strength. 3. By weight%, Al: 0.8 to 7%, Ti: 0.8 to 7%, Mo: 13
-25%, Cr: 8-16%, Ta: 1.1-8%, S
i: 2.5% or less, Mn: 3% or less, N: 0.0001
.About.0.1%, C: 0.1% or less, and further Co: 0.1-5%, V: 0.1-0.5%, W: 0.
A Ni-based superheat-resistant alloy for a mold, which contains 1 to 2% or more of 1 to 4% and the rest is Ni and unavoidable impurities and is excellent in oxidation resistance and high-temperature strength. 4. By weight%, Al: 0.8 to 7%, Ti: 0.8 to 7%, Mo: 13
-25%, Cr: 8-16%, Ta: 1.1-8%, S
i: 2.5% or less, Mn: 3% or less, N: 0.0001
To 0.1%, C: 0.1% or less, Nb: 0.1 to 1%, Hf: 0.1 to 2%, Cu: 0.
A Ni-based super heat-resistant alloy for a mold, which contains 1 or 2 or more of 1 to 2% and the balance is Ni and unavoidable impurities and is excellent in oxidation resistance and high-temperature strength. 5. By weight%, Al: 0.8 to 7%, Ti: 0.8 to 7%, Mo: 13
-25%, Cr: 8-16%, Ta: 1.1-8%, S
i: 2.5% or less, Mn: 3% or less, N: 0.0001
.About.0.1%, C: 0.1% or less, Fe: 0.01 to 6%, B: 0.001 to 0.1%, Z
r: 0.001-0.1%, Ca: 0.001-0.0
1% or more of 1%, and further C
o: 0.1-5%, V: 0.1-0.5%, W: 0.1
Ni-based super heat-resistant alloy for molds, which contains one or more of 4% to 4% and the rest is Ni and unavoidable impurities and is excellent in oxidation resistance and high-temperature strength. 6. By weight%, Al: 0.8 to 7%, Ti: 0.8 to 7%, Mo: 13
-25%, Cr: 8-16%, Ta: 1.1-8%, S
i: 2.5% or less, Mn: 3% or less, N: 0.0001
.About.0.1%, C: 0.1% or less, Fe: 0.01 to 6%, B: 0.001 to 0.1%, Z
r: 0.001-0.1%, Ca: 0.001-0.0
1% or more of 1%, and further N
b: 0.1 to 1%, Hf: 0.1 to 2%, Cu: 0.1
Ni-based super heat-resistant alloy for molds, which contains one or more of 2% to 2% and the rest is Ni and unavoidable impurities and is excellent in oxidation resistance and high-temperature strength. 7. By weight, Al: 0.8 to 7%, Ti: 0.8 to 7%, Mo: 13
-25%, Cr: 8-16%, Ta: 1.1-8%, S
i: 2.5% or less, Mn: 3% or less, N: 0.0001
To 0.1%, C: 0.1% or less, Co: 0.1 to 5%, V: 0.1 to 0.5%, W: 0.
1 to 2% of 1 to 4%, or more, Nb: 0.1 to 1%, Hf: 0.1 to 2%, Cu:
Containing one or more of 0.1 to 2%,
A Ni-base super heat-resistant alloy for molds, which is excellent in oxidation resistance and high-temperature strength, the balance being Ni and inevitable impurities. 8. In weight%, Al: 0.8 to 7%, Ti: 0.8 to 7%, Mo: 13
-25%, Cr: 8-16%, Ta: 1.1-8%, S
i: 2.5% or less, Mn: 3% or less, N: 0.0001
.About.0.1%, C: 0.1% or less, Fe: 0.01 to 6%, B: 0.001 to 0.1%, Z
r: 0.001-0.1%, Ca: 0.001-0.0
1% or more of 1%, and further C
o: 0.1-5%, V: 0.1-0.5%, W: 0.1
1% or more of 4% to 4%, Nb: 0.1 to 1%, Hf: 0.1 to 2%, Cu: 0.
A Ni-based super heat-resistant alloy for a mold, which contains 1 or 2 or more of 1 to 2% and the balance is Ni and unavoidable impurities and is excellent in oxidation resistance and high-temperature strength.