JPH07331368A - Age hardening nickel-base alloy material, excellent in strength and corrosion resistance, and its production - Google Patents

Abstract

PURPOSE:To obtain an age hardening Ni-base alloy material excellent in strength and corrosion resistance by specifying a composition consisting of Ni, Cr, Ti, Nb, Al, Mo, W, B, Cu, and Fe, controlling impurities, and forming a specific structure. CONSTITUTION:This age hardening Ni-base alloy material can be obtained by providing a composition, which consists of, by weight, 48-55% Ni, 17-25% Cr, 0.4-2.5% Ti, 4-6% Nb, 0.3-0.8% Al, Mo and W in the range satisfying 2.5<=Mo+1/2W<=5%, 0-0.01% B, 0-2% Cu, and the balance Fe with inevitable impurities and in which C, N, Si, Mn, P, and S among these impurities are regulated to <=0.3%, <=0.01%, <=0.3%, <=0.3%, <=0.015%, and <=0.005%, respectively, and also providing a structure in which the formation of intermetallic compound and carbide is prevented in crystalline grain boundaries. This alloy material can be economically obtained by subjecting an alloy with the above composition to heating and holding at 980-1080 deg.C for 1min-2hr and to forced cooling to undergo solution heattreatment and then subjecting it to heating and holding at 680-730 deg.C for 5-10hr to undergo aging treatment.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an age hardening type nickel base alloy material having good corrosion resistance in a corrosive environment, particularly in an environment containing one or more of hydrogen sulfide, carbon dioxide and chlorine ions. Regarding

[0002]

2. Description of the Related Art Structural members for oil wells, chemical industry and geothermal power generation are required to have high strength and high corrosion resistance. Corrosion which is a problem here is mainly pitting corrosion, crevice corrosion, intergranular corrosion and stress corrosion cracking under the above-mentioned environment.

Age-hardening alloy materials have hitherto been applied to thick-walled or specially shaped metal members which are used for the above-mentioned applications and whose strength cannot be increased by cold working.

Among age-hardening type nickel-base alloys among the above alloy materials, Alloy 718 (trade name: ASTM UNS No. N07718) is used.
) Is most commonly used. But Alloy 718
Since it was originally developed as a high-temperature material, there are some with high C and N contents, and it cannot be said that the corrosion resistance is sufficient.

Regarding Alloy 718, a report of using a low C material for the purpose of improving fatigue characteristics in a high temperature environment (for example, T. Bani
k and others: Proc.Superalloys 718,625 and Various Derivat
ives, TMS (1991), P.913-924), but the heat treatment conditions have not been optimized as a corrosion resistant material. In addition, Alloy71 is used in NACE MR0175 for materials used in oil well environments.
Although the upper limit of hardness of 8 (HRC ≤ 40) is specified, there is no particular specification for heat treatment conditions, and aging treatment is generally applied to high temperature applications at 775 to 800 ° C for 6 to 8 hours. Has been done.

Al as a high corrosion resistance age hardening type nickel base alloy
loy 725 (trade name: UNS No.N07725) and Alloy 625 Plus (trade name: UNS No.N07716) are known, but both Ni ≧ 55% and Mo ≧ 7 in order to improve corrosion resistance and structural stability. It becomes expensive in%.

As a method for improving the corrosion resistance of an age-hardening nickel-base alloy, a system containing only Nb (Japanese Patent Publication No. 63-1387)
, Nb-Al composite additive system (Japanese Patent Publication No. 1-14992) and Ti, Nb, Al composite additive system (Japanese Patent Publication No. 5-40011), 0.2% proof stress is 825MPa (120ksi) or more. The aging condition satisfying the condition is substantially 20 hours or more, which is not economical in manufacturing. Furthermore, the nickel-based alloy disclosed in Japanese Patent Publication No. 5-40011 requires the addition of Mn, but Mn in molten nickel alloy or molten steel has a high vapor pressure and is usually applied to the production of this type of alloy. Special attention is required for vacuum melting such as VIM (vacuum induction melting) and VAR (vacuum arc remelting).

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to provide the above-mentioned corrosive environment containing hydrogen sulfide, etc.
Alloy 718 has poor corrosion resistance, but expensive Alloy
No. 725 and Alloy 625 Plus are suitable for use in a corrosive environment that is inferior to the use of Alloy 625 Plus, and an age-hardening nickel-base alloy material and a method for producing the same that do not significantly increase the production cost.

[0009]

The present inventors have found that Alloy 71
We investigated the effect of trace components and heat treatment conditions on strength and corrosion resistance, using No. 8 as the basic composition, and found conditions under which corrosion resistance can be significantly improved without significantly increasing manufacturing costs.

The gist of the present invention resides in the following age-hardening nickel-base alloy materials (1) and (2) and the manufacturing methods thereof (3) and (4).

(1)% by weight, Ni: 48 to 55%, Cr: 17 to 25
%, Ti: 0.4 to 2.5%, Nb: 4 to 6%, Al: 0.3 to 0.8
% And Mo alone or Mo + W: 2.5% ≦ [Mo + (1/2)
W] ≦ 5%, and further B: 0 to 0.01% and Cu: 0
~ 2% of one or more, the balance consisting of Fe and unavoidable impurities, C in the impurities is 0.01% or less, N is 0.01% or less, Si is 0.3% or less, Mn is 0.3% or less, P is 0.015% The following and S are 0.005% or less, and an age-hardening type nickel-base alloy material excellent in strength and corrosion resistance having a structure in which the formation of intermetallic compounds and carbides at grain boundaries is prevented.

(2) In the component of (1) above, the relationship between the Ti equivalent calculated by the following formula and the R value calculated by the following formula satisfies the following formula or An age-hardening nickel-base alloy material having a structure in which the formation of carbides is prevented and having excellent strength and corrosion resistance.

Ti equivalent = Ti (%) + 0.52Nb (%) ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ R = 2.3 [C (%) + N (%)] + 65 [C (%) + N (%)] ²・ ・ ・ When Ti equivalent ≦ 3.5, R ≦ (0.02 × Ti equivalent) ・ ・ ・ ・ ・ ・ ・ ・ When Ti equivalent> 3.5, R ≦ 0.07 ・ ・ ・・ ・ ・ ・ ・ ・ (3) 980 to 108
After heating and holding at 0 ° C for 1 minute to 2 hours, a solution treatment of cooling to room temperature at a cooling rate of air cooling or more is performed, and then 680 to
A process for producing an age-hardening nickel-base alloy material excellent in strength and corrosion resistance, which is a structure in which the formation of intermetallic compounds and carbides is prevented at grain boundaries by subjecting to an aging treatment by heating and holding at 730 ° C for 5 to 10 hours .

(4) A raw material nickel-base alloy having the component of the above (1) and the Ti equivalent determined by the above equation (2) is
After heating and holding at 80 to 1080 ° C for 1 minute to 2 hours, a solution treatment of cooling to room temperature at a cooling rate of air cooling or more is performed, and then,
A structure in which an aging treatment of heating and holding at 680 to 730 ° C. for 5 to 10 hours is performed, the R value obtained by the above formula satisfies the above formula or, and the formation of intermetallic compounds and carbides at grain boundaries is prevented. A method for producing an age hardening type nickel-base alloy material having excellent strength and corrosion resistance.

In each of the above nickel-base alloy materials and their materials, neither B nor Cu may be added. When positively contained, the lower limits are preferably 0.0005% for B and 0.01% for Cu.

The R value in the above formula means the Ti equivalent in the extraction residue, and hereinafter, R is described as R [Ti] eq. And Ti equivalent as [Ti] eq.

[0017]

First, the reasons for limiting the chemical composition of the nickel-base alloy material of the present invention and the material alloy to which the method for producing the same is applied will be explained. % Means% by weight.

Ni: 48-55% Ni is not only a constituent element of the γ'phase and γ "phase, but also
The balance between the contents of Cr and Mo has the effect of suppressing the formation of intermetallic compounds such as σ, μ and Laves phases, which are unfavorable for ductility, toughness and corrosion resistance, and stabilizing the austenite matrix. To obtain these effects, the Ni content needs to be 48% or more. On the other hand, 55
%, The hydrogen cracking resistance cannot be ensured.
The upper limit of the content is 55%.

Cr: 17-25% Cr improves corrosion resistance together with Mo. To obtain this effect, the Cr content needs to be 17% or more. On the other hand, if it exceeds 25%, the hot workability deteriorates, and σ, μ and
Intermetallic compounds such as s phase and carbides such as M ₂₃ C ₆ and M ₆ C are easily generated, which deteriorates ductility, toughness and corrosion resistance.

Ti: 0.4 to 2.5% Ti is mainly precipitated as a γ'phase and contributes to the increase in strength.
If the Ti content is less than 0.4%, this effect is insufficient. On the other hand, if it exceeds 2.5%, coarsening of the γ'phase is promoted and ductility and toughness are reduced.

Nb: 4 to 6% Nb is mainly precipitated as a γ ″ phase, which contributes to the increase in strength and improves the corrosion resistance. These effects become remarkable when the Nb content is 4% or more. , Σ above 6%,
It tends to form intermetallic compounds such as μ and Laves phases, which are unfavorable for ductility, toughness and corrosion resistance.

Al: 0.3 to 0.8% Added as a deoxidizing agent. Al also stabilizes the precipitation of the γ'phase and γ "phase. These effects are not sufficient if the Al content is less than 0.3%. On the other hand, if it exceeds 0.8%, oxide-based inclusions increase. And deteriorates corrosion resistance.

Mo alone or Mo + W: 2.5% ≦ [Mo + (1 /
2) W] ≦ 5% Mo coexists with Cr to improve pitting corrosion resistance, so it must be added. This effect has a Mo content of 2.
It becomes remarkable at 5% or more. However, if it exceeds 5%, the hot workability is deteriorated, and further intermetallic compounds such as σ, μ and Laves phase and carbides such as M ₆ C are apt to be generated, and ductility, toughness and corrosion resistance are deteriorated. Therefore, the range of containing Mo alone is set to 2.5 to 5%.

Even if a part of Mo is replaced with twice as much W, the same effect can be obtained. Therefore, the range in the case of adding Mo and W in combination is 2.5% ≦ [Mo + (1/2) W] ≦ 5%.

C: 0.01% or less C increases the amount of undissolved carbides, especially NbC, and deteriorates the pitting corrosion resistance. In addition, Ti and Nb are precipitated as a solution, which causes aging treatment. The amount of precipitated γ'phase and γ "phase is reduced, and sufficient hardening cannot be obtained. Furthermore, the grain boundary precipitation of M ₂₃ C ₆ and M ₆ C type carbides is promoted during the aging treatment. , C content was 0.01% or less, preferably 0.007% or less.

N: 0.01% or less N increases the amount of undissolved nitrides, particularly TiN, and deteriorates the pitting corrosion resistance. In addition, Ti and Nb are precipitated in the solution state, so that the aging treatment is performed. As a result, the precipitation amount of the γ'phase and the γ "phase is reduced and sufficient hardening cannot be obtained. Therefore, the N content is set to 0.01% or less, preferably 0.007% or less.

Si: 0.3% or less Added as a deoxidizing agent. However, if the Si content exceeds 0.3%, intermetallic compounds such as σ phase, which are unfavorable for ductility and toughness, are likely to be formed at the grain boundaries. 0 is preferred.
It is 1% or less.

Mn: 0.3% or less Added as a desulfurizing agent. However, when the Mn content exceeds 0.3%, oxide-based and sulfide-based inclusions increase and the pitting corrosion resistance deteriorates.

P: 0.015% or less If the P content exceeds 0.015%, the hot workability is deteriorated due to the segregation of grain boundaries. In addition, the corrosion resistance also deteriorates, so 0.01
It was set to 5% or less.

S: 0.005% or less When the S content exceeds 0.005%, the hot workability is deteriorated due to the segregation of grain boundaries. It also deteriorates corrosion resistance, so 0.0
It was less than 05%.

The nickel-base alloy material and the material alloy thereof according to the present invention may further contain one or two of B and Cu. None of them may be added.

B: 0 to 0.01% B improves hot workability and toughness, so is added as necessary. When positively contained for this purpose, the B content is preferably 0.0005% or more. But 0.01
%, The effects are saturated, so the upper limit of the B content is 0.01%.

Cu: 0 to 2% Since Cu contributes to the formation of a corrosion resistant film, it is added if necessary. When positively contained for this purpose, the Cu content is preferably 0.01% or more. However, if it exceeds 2%, the precipitation of γ'phase and γ "phase that contribute to strength is prevented and the intergranular precipitation of intermetallic compounds such as δ phase, which is not preferable for ductility and toughness, is promoted. Was set to 2%.

One of the nickel-based alloy materials of the present invention has the above-mentioned components and a structure in which the formation of intermetallic compounds and carbides is prevented at the grain boundaries, and the corrosion resistance is improved.

Another one of the nickel-based alloy materials of the present invention is
Furthermore, the relationship between [Ti] eq. Obtained by the following equation and R value obtained by the following equation, that is, R [Ti] eq., Satisfies the following equation or:

[Ti] eq. = Ti (%) + 0.52Nb (%) ... R [Ti] eq. = [C (%) + N (% )] +65 [C (%) + N (%)] ²・ ・ ・ [Ti] eq. ≦ 3.5, R [Ti] eq. ≦ (0.02 × [Ti] eq.) ··· [Ti] eq. > 3.5, R [Ti] eq. ≤0.07 ... Here, the above formula corresponds to the definition of [Ti] eq. In the present invention, and nickel in the material stage is used. The same applies to the base alloy. R in the above formula means that it is in the extraction residue, and this formula also shows an estimated value of the amount of undissolved carbonitride after solution treatment.

The reason for limiting the above conditions will be described with reference to FIGS.

First, in order to estimate the amount of undissolved carbonitride in the as-solution state for nickel-based alloys having various C and N contents, the extraction residue was sampled and the amounts of Ti and Nb in the residue were measured. Then, the results shown in Table 1 and FIG. 1 were obtained.

[0039]

[Table 1]

FIG. 1 shows R [Ti] eq. And [C] after solution treatment.
It is a figure which shows the relationship with + [N].

As shown in Table 1 and FIG. 1, the relation between R [Ti] eq. And [C] + [N] was obtained by regression calculation using the first-order approximation formula and the second-order approximation formula. The two lines shown in Figure 1 were obtained. Of the two lines, the quadratic approximation formula shown by the broken line with high fitting property was adopted. This equation is the above equation.

Further, before determining the aging treatment temperature condition which will be described later, first, [Ti] eq. And R [Ti] in the formulas described later in order to ensure the effects of low C and low N.
By determining the relationship with eq., the effective Ti and Nb amounts (hereinafter, E
[Ti] eq.).

FIG. 2 shows R [Ti] in the alloy material of the present invention.
It is a figure which shows the relationship between eq. and [Ti] eq. Especially [Ti]
In the alloy of eq. ≦ 3.5, the amount of precipitation strengthening is originally small, so even if the contents of Ti and Nb are the same, from the viewpoint of improving the strength (YS), in order to secure E [Ti] eq. The amount of R [Ti] eq. Precipitated as inclusions is 2% or less of that of [Ti] eq. On the other hand, in the alloy of [Ti] eq.> 3.5, the amount of undissolved carbonitrides is suppressed and carbides at grain boundaries are For the purpose of preventing precipitation, it is preferable that R [Ti] eq. ≦ 0.07.

That is, the relationship between the [Ti] eq. Of the above equation and the R [Ti] eq. Representing the estimated amount of undissolved carbonitride in the extraction residue obtained by the above equation particularly satisfies the following equations and By subjecting the alloy to a heat treatment described below, excellent ductility and toughness as well as corrosion resistance can be imparted.

When [Ti] eq. ≤3.5, R [Ti] eq. ≤ (0.02 x [Ti] eq.) ・ ・ When [Ti] eq.> 3.5, R [Ti] eq. ≤0.07 ・..... Further, nickel-based alloys with various C and N contents are aged, and two test pieces are prepared for each composition into a solution specified by JIS G0578 (6% FeCl After immersion in ₃ ) at 50 ° C. for 24 hours, the presence or absence of pitting corrosion was observed to obtain FIG.

FIG. 3 shows R [Ti] eq.
It is a figure which shows the relationship between [C] + [N]. As can be seen from FIG. 3, in the case of high C and high N, the pitting corrosion resistance deteriorates. This is because undissolved inclusions increase, and ductility and toughness also decrease.

From the results of FIG. 1 and FIG. 3, in order to achieve one of the objects of the present invention to obtain an alloy material having excellent pitting corrosion resistance, [Ti] eq. And R [Ti] eq. It turns out that it is necessary to clarify the relationship.

FIG. 4 shows aging treatment at 650 to 800 ° C. × 8 hAC for two kinds of alloys having different contents of C and N (Examples described later, alloys of Nos. 1 and 6 in Table 2). Strength (YS) when applied, hardness, toughness and ASTM A262 Practice
It is a figure which shows the intergranular corrosion weight loss by B. According to these results, when both the contents of C and N are reduced, the effective Ti and Nb amounts (E [Ti] e) that contribute to the precipitation strengthening of the γ'phase and the γ "phase are reduced.
q.) is increased, the strength (YS) is increased by about 100 MPa and the toughness (absorbed energy) is dramatically improved even if the aging treatment is performed under the same conditions. For example, under the conditions of the present invention, alloy No. 1 in Table 2 has a predetermined high strength (YS ≧ 825).
(MPa) and toughness of 60 J or more are satisfied at the same time, NACE hardness upper limit (HRC ≦ 40) is not exceeded, and intergranular corrosion resistance is extremely excellent. On the other hand, conventional alloy (alloy No. in Table 2
In 6), it is not possible to obtain one that simultaneously satisfies strength, toughness and intergranular corrosion resistance.

The effective Ti and Nb amounts (E [Ti] eq.) Are
It is calculated by the following formula.

E [Ti] eq. = [Ti] eq.-R [Ti] eq .. The reason why the strength, toughness and intergranular corrosion resistance are improved is as follows.
A description will be given based on FIG.

FIG. 5 is a diagram showing precipitation regions of the δ phase and M ₆ C depending on the aging treatment conditions. When both C and N contents are reduced and E [Ti] eq. Is increased, δ phase and carbide M ₆ C
The precipitation curve of is the solid line in the figure. In this case, the conventional condition lies in the precipitation region of the δ phase, and the δ phase easily precipitates at the grain boundaries, and good results cannot be obtained in terms of strength, toughness and intergranular corrosion resistance. . However, when the above-mentioned conditions of the present invention are satisfied, neither precipitation of the carbide M ₆ C nor the δ phase occurs, and E [Ti] eq. It is possible to have all of the intergranular corrosion resistance.

Incidentally, even in the conventional high C and high N alloys, the conditions defined in the present invention are that the precipitation region of δ phase and M ₆ C (see FIG. 5).
Although it is outside the broken line in the middle), since E [Ti] eq. Is low, strength and / or toughness are insufficient, and intergranular corrosion resistance is not always good.

Next, the reasons for limiting the manufacturing process and processing conditions will be described.

Material Nickel-based alloy is preferably melted by VIM (vacuum induction melting), VAR (vacuum arc remelting, etc.) according to a conventional method, and then hot forging and hot working (rolling, extrusion) as required. Etc.) and cold working to obtain the product shape.

In the production method of the present invention, the above-mentioned processed nickel-base alloy material is heated and held at 980 to 1080 ° C. for 1 minute to 2 hours and then solution-treated to cool it to room temperature at a cooling rate of air cooling or higher. Then, an aging treatment of heating and holding at 680 to 730 ° C. for 5 to 10 hours is performed.

Solution heat treatment condition: γ ′ phase and γ ″ by aging treatment
Appropriate solution treatment is required to effectively precipitate the phases. If the solution temperature is lower than 980 ° C, precipitation of δ phase or Laves phase may occur.

On the other hand, if the temperature exceeds 1080 ° C., the crystal grains become coarse and the ductility and toughness are impaired.

The holding time is required to be 1 minute or more so that the precipitate is completely solid-dissolved and the intermetallic compound and the carbide are not present at the grain boundaries. On the other hand, the target of grain size
The holding time was set to 2 hours or less in order to satisfy ASTMGS No. ≦ 3. The cooling condition after the holding must be a condition capable of preventing the intermetallic compounds and carbides from precipitating at the grain boundaries by cooling to room temperature at a cooling rate of air cooling or higher. Particularly, it is desirable that the cooling rate between 980 and 730 ° C at which the above-mentioned precipitates are easily deposited is 10 ° C / min or more.

Aging treatment conditions: In the age hardening type nickel-base alloy material of the present invention, it is desirable that the 0.2% proof stress satisfies 825 MPa (120 ksi) or more. In order to achieve this target property, the contents of C and N are suppressed to low values, and the effective Ti and Nb amounts that contribute to precipitation strengthening are increased. The deposition nose has shifted to the short side. Therefore, as shown in FIG. 5, the aging temperature should be set to avoid the high temperature side of 775 to 800 ° C, which is the inside of the precipitation nose,
The temperature range was 680 to 730 ° C.

If the aging time is less than 5 hours, sufficient strength cannot be obtained. On the other hand, if the heating time exceeds 10 hours, not only the heating cost will increase, but also the γ'phase and the γ "phase will be coarsened, and the ductility and toughness will be reduced. In addition, intermetallic compounds and carbides will precipitate at grain boundaries, and Deteriorates toughness and corrosion resistance.

[0061]

【Example】

<Sample Material> An alloy having the composition shown in Table 2 was manufactured and hot-forged into a round bar having a diameter of 50 mmφ.

[0062]

[Table 2]

<Test Method> In the structure observation, grain boundary precipitates were identified by grain size determination and a transmission electron microscope. In terms of mechanical properties, a room temperature tensile test using a test piece with a diameter of 6 mmφ × 30 mm GL and a 0 mm test with a test piece of 5 mm × 10 mm-2 mm V notch
A Charpy impact test and hardness test (HRC) at 0 ° C were performed. The corrosion resistance test was carried out by the following method to evaluate pitting corrosion, intergranular corrosion, and stress corrosion cracking in hydrogen sulfide.

In the pitting corrosion test, after immersing in a solution (6% FeCl ₃ ) specified in JIS G0578 at 50 ° C. for 24 hours, the presence or absence of pitting corrosion was observed. In the intergranular corrosion test, ASTM A262 Practi
The solution described in ce B [2.5% Fe ₂ (SO ₄ ) ₃ + 50% H ₂
SO ₄ ] was boiled and immersed for 120 hours, and then the corrosion weight loss was measured. In the stress corrosion cracking test, a 4-point bending test piece is loaded with 100% stress of 0.2% proof stress, and 25% NaCl + 0.5% CH ₃ COOH.
＋ 8atmH ₂ S + 1g / liter S (sulfur) solution at 180 ℃
After immersion for 14 days, the presence or absence of cracks was confirmed.

(Test 1) After solution heat treatment at 1025 ° C. for 5 minutes WQ 700
After aging treatment at ℃ × 8hAC, identification of grain boundary precipitates, mechanical test and corrosion resistance test were performed. The results are shown in Table 3.

[0066]

[Table 3]

As is clear from Table 3, the alloy material produced under the conditions defined by the present invention can maintain excellent corrosion resistance without impairing the strength and toughness.

(Test 2) The sample material No. 1 was treated by appropriately combining the solution heat treatment conditions shown in Table 4 and the aging treatment conditions shown in Table 5. Table 6 shows the test results.

[0069]

[Table 4]

[0070]

[Table 5]

[0071]

[Table 6]

As is clear from Table 6, the alloy material produced under the conditions defined by the present invention can maintain excellent corrosion resistance without impairing the strength and toughness.

[0073]

According to the present invention, it is possible to obtain an age hardening type nickel base alloy material having excellent strength, ductility, toughness and corrosion resistance. This alloy material has high corrosion resistance because intermetallic compounds and carbides do not exist in the crystal grain boundaries, and is used in environments including hydrogen sulfide, carbon dioxide and chlorine ions such as in oil wells, chemical industry, and geothermal power generation. It is suitable for structural members.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between R [Ti] eq. And [C] + [N] after solution treatment obtained by regression calculation.

FIG. 2 shows R [Ti] eq. And [Ti] in the alloy material of the present invention.
It is a figure which shows the relationship with eq.

FIG. 3 is a diagram showing the relationship between R [Ti] eq. And [C] + [N] after solution treatment, which affects the pitting corrosion occurrence rate.

FIG. 4 is a diagram showing the effect of aging treatment conditions on the properties of a nickel-based alloy material.

FIG. 5 is a diagram showing a precipitation region of a δ phase and M ₆ C depending on an aging treatment condition.

Claims (4)

[Claims] 1. By weight%, Ni: 48-55%, Cr: 17-25%,
Ti: 0.4 to 2.5%, Nb: 4 to 6%, Al: 0.3 to 0.8% and Mo alone or Mo + W: 2.5% ≦ [Mo + (1/2) W] ≦
5%, B: 0-0.01% and Cu: 0-2%
1 or more of the above, the balance consisting of Fe and unavoidable impurities, C in the impurities is 0.01% or less, N is 0.01% or less, Si is
0.3% or less, Mn is 0.3% or less, P is 0.015% or less, and S is 0.005% or less, and the strength is characterized by having a structure in which the formation of intermetallic compounds and carbides is prevented at grain boundaries. Age-hardening nickel-based alloy material with excellent corrosion resistance. 2. By weight%, Ni: 48-55%, Cr: 17-25%,
Ti: 0.4 to 2.5%, Nb: 4 to 6%, Al: 0.3 to 0.8% and Mo alone or Mo + W: 2.5% ≦ [Mo + (1/2) W] ≦
5%, B: 0-0.01% and Cu: 0-2%
1 or more of the above, the balance consisting of Fe and unavoidable impurities, C in the impurities is 0.01% or less, N is 0.01% or less, Si is
0.3% or less, Mn is 0.3% or less, P is 0.015% or less and S is 0.005% or less, and Ti calculated by the following formula
Excellent strength and corrosion resistance, characterized in that the relationship between the equivalent weight and the R value calculated by the following formula satisfies the following formula or Age hardening type nickel base alloy material. Ti equivalent = Ti (%) ＋ 0.52Nb (%) ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ R = 2.3 [C (%) ＋ N (%)] ＋65 [C (%) ＋ N (% )] ²・ ・ ・ When Ti equivalent ≦ 3.5, R ≦ (0.02 × Ti equivalent) ・ ・ ・ ・ ・ ・ When Ti equivalent> 3.5, R ≦ 0.07 ・ ・ ・ ・ ・ ・... 3. By weight%, Ni: 48-55%, Cr: 17-25%,
Ti: 0.4 to 2.5%, Nb: 4 to 6%, Al: 0.3 to 0.8% and Mo alone or Mo + W: 2.5% ≦ [Mo + (1/2) W] ≦
5%, B: 0-0.01% and Cu: 0-2%
1 or more of the above, the balance consisting of Fe and unavoidable impurities, C in the impurities is 0.01% or less, N is 0.01% or less, Si is
980-based material nickel-based alloys with 0.3% or less, Mn 0.3% or less, P 0.015% or less and S 0.005% or less
After heating and holding at 1080 ℃ for 1 minute to 2 hours, solution heat treatment is performed to cool to room temperature at a cooling rate higher than air cooling, and then 680
Age-hardening nickel with excellent strength and corrosion resistance, characterized by having a structure in which the formation of intermetallic compounds and carbides is prevented at grain boundaries by performing an aging treatment by heating and holding at ~ 730 ° C for 5-10 hours. Method for manufacturing base alloy material. 4. By weight%, Ni: 48-55%, Cr: 17-25%,
Ti: 0.4 to 2.5%, Nb: 4 to 6%, Al: 0.3 to 0.8% and Mo alone or Mo + W: 2.5% ≦ [Mo + (1/2) W] ≦
5%, B: 0-0.01% and Cu: 0-2%
1 or more of the above, the balance consisting of Fe and unavoidable impurities, C in the impurities is 0.01% or less, N is 0.01% or less, Si is
0.3% or less, Mn is 0.3% or less, P is 0.015% or less and S is 0.005% or less, and Ti calculated by the following formula
Equivalent weight material nickel-based alloy
After heating for 2 minutes to hold for 2 minutes, solution treatment is performed to cool to room temperature at a cooling rate of air cooling or higher, and then aging treatment is performed by heating and holding at 680 to 730 ° C for 5 to 10 hours. Satisfying the following formula or, and having a structure in which the formation of intermetallic compounds and carbides at grain boundaries is prevented, a method for producing an age-hardening nickel-based alloy material having excellent strength and corrosion resistance. Ti equivalent = Ti (%) ＋ 0.52Nb (%) ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ R = 2.3 [C (%) ＋ N (%)] ＋65 [C (%) ＋ N (% )] ²・ ・ ・ When Ti equivalent ≦ 3.5, R ≦ (0.02 × Ti equivalent) ・ ・ ・ ・ ・ ・ When Ti equivalent> 3.5, R ≦ 0.07 ・ ・ ・ ・ ・ ・...