JPS63274747A - Manufacture of heat-resisting metallic material - Google Patents

Abstract

PURPOSE:To efficiently produce a material excellent in heat resistance by simplified means, by applying solution heat treatment to an Ni-Cr-Fe-type heat- resisting stock to which Nb is added and by subjecting the above to area- reducing cold working and then to aging treatment under specific conditions. CONSTITUTION:A heat-resisting metal stock having a composition consisting of, by weight ratio, 45-60% Ni, 15-25% Cr, 3-7% (Nb+Ta), 2-5% Mo, <0.1% C, and the balance Fe with inevitable impurities or to which 0.1-1.0% Al and/or 0.1-1.5% Ti is further added is subjected to solution heat treatment at 900-1,250 deg.C, which is then subjected to cold working accompanied by 10-80% reduction in area. Subsequently, aging treatment is applied at a temp. in range represented by an equation, t=2.5d+C [where (t) means aging temp., (d) means reduction in area attendant upon cold working before aging treatment, and C means a constant of 770-820), for 0.5-8hr. In this way, the heat-resisting metallic material such as spring material can be efficiently manufactured by means of the existing equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing metal materials that are used for nuclear power, air combat, automobiles, etc. and require a high degree of heat resistance.

<Prior Art> Conventionally, metal materials called high alloys or superalloys, which contain many types and contents of alloying elements, have been used as heat-resistant members that are subjected to high stress in high-temperature environments.

Go-based alloys were the first to be put to practical use as such materials, but they were avoided due to poor workability, and precipitation-strengthened Ni-based alloys gradually became mainstream.

This type of alloy is generally hard Ni3#.

The main precipitated phase is Ni3Tj, which is subjected to solution treatment and then aging treatment to uniformly and finely precipitate it in the matrix, thereby increasing high-temperature strength. Therefore, it is also characterized by relatively good workability before precipitation strengthening treatment.

In the past, this type of alloy was only used in parts for nuclear power plants, but in recent years the market has been rapidly expanding as a heat-resistant spring material for aircraft shell parts, engine parts, automobile parts, etc.

In addition, the need for performance improvement has increased, and in addition to the conventional addition of M1L, yang is added, and products further strengthened by a new precipitated phase of Chen 3yang are also being used.

Among these, high-temperature alloys and precipitation-strengthened alloys containing Ta, which is difficult to separate from high-temperature alloys, in excess of 3% by weight, are attracting attention because of their excellent high-temperature strength.

<Problems to be Solved by the Invention> However, in order to obtain the desired performance of this type of alloy, conventionally, as an aging treatment for a high Nb-added alloy, a filtration process was performed.
The temperature is maintained at 700 to 800°C for about 10 hours to cause the nuclei of the precipitated phase to appear uniformly and finely.

(2 furnace cooling to 80-150℃, including furnace cooling time,
Holding is performed for about 10 hours to promote aging precipitation.

gauze There was a long period of time spent dealing with the matter.

However, the mechanism of the aging reaction of this type of alloy has not been clearly elucidated, and the aging conditions described above also have strong empirical elements. Furthermore, when performing cold working for strengthening after solution treatment, it is necessary to consider the influence of the area reduction rate during cold working on the subsequent aging conditions.

<Means for Solving the Problems> The present invention aims to solve the problems of the above-mentioned conventional methods, and as a result of studies, it was discovered based on detailed experiments and statistical methods that a highly positive additive N having excellent heat resistance was used. , a method for producing a base alloy, comprising:
A metal material having heat resistance strength comparable to that of the conventional method can be obtained using a simple method not available in the conventional method.

That is, this invention uses 45 to 60% Ni and 15% Cr by weight.
~25%, positive + Ta 3~7%, -2~5%,
A heat-resistant metal material in which unavoidably mixed C is limited to less than 0.1%, and the remainder is Fe and unavoidable impurities, or further N001-1.0%, TL O11-1.
After solution treatment of heat-resistant metal 'fA44 with 5% of one or two added at 900-1250°C, 10-8
Cold working with 0% cross-section reduction and then t =
-2,56+ C (@shi, t: aging treatment temperature, d: area reduction rate due to cold working before aging treatment, 10 to 80, C near 70 to 8
The present invention provides a method for producing a heat-resistant metal material, which is characterized in that an aging treatment is performed for 0.5 to 8 hours at a temperature within the range shown by the equation (constant of 20).

<Function> After solution treatment, this type of alloy is often subjected to cold working in order to increase its heat resistance strength. The cross-sectional reduction rate in this case is
The larger the size, the higher the heat resistance strength after aging treatment, but on the other hand, the toughness decreases, so it is necessary to take an appropriate area reduction rate depending on the usage environment.

The appropriate range of the area reduction rate is 10 to 80%,
Strong processing in which this value exceeds 80% is accompanied by embrittlement, and 10%
If it is less than that, the effect of improving heat resistance strength by cold working is weak.

Since this invention was discovered based on the following consideration procedure, it is possible to use a simple aging treatment for any area reduction rate within the above-mentioned area reduction rate range, and it can be used in a simple aging treatment, which is conventionally complicated and takes a long time. It is possible to obtain a metal material with excellent heat resistance and strength comparable to that obtained by aging treatment.

The following is an explanation based on the examination procedure.

(1) First, as a material, *5 with the composition shown in Table 1 below.
The cross-section reduction rate before C2JW# effect treatment, the temperature and time of aging treatment were carried out under the combination of manufacturing conditions shown in the process chart in Table 2, and samples of the same size but under different manufacturing conditions were created. Since this invention aims to obtain excellent heat resistance strength under simple aging treatment conditions, a so-called one-stage aging treatment in which the aging temperature is constant is used.

211 For comparison, a sample subjected to aging treatment according to the conventional process shown in FIG. 2 was also prepared.

(3) (The samples prepared in step 21 were subjected to high-temperature tensile tests along with comparative samples at test temperatures of 400°C, 500°C, 600°C, and 700°C.

(Based on the data obtained in 41 [3], multiple regression analysis was carried out to quantify the relationship between area reduction rate 1 aging degree, aging time and high temperature tensile strength for each test Mfi degree.

As a result, t = -2,5d-+-C (@shi, t: aging treatment temperature, d: area reduction rate due to cold working before aging treatment, constant of 10 to 80, C near 70 to 820) It has become clear that if the aging treatment is carried out for 0.5 to 8 hours at a temperature within the range shown by the formula, a heat resistance strength comparable to that obtained by conventional aging treatment can be obtained.

Part of the data obtained through the above consideration procedure is shown in FIGS. 3 and 4. All are shown in contour diagrams, and the numbers in the diagram are the high-temperature tensile strength at a test temperature of 500°C, and Figure 3 shows the aging time when the area reduction rate due to cold working before aging treatment is 40%. , which shows the relationship between aging temperature and high temperature strength.

Also, Figure 4 shows that the statute of limitations is 51! This figure shows the relationship between the cross-section reduction rate due to cold working before aging, aging temperature, and high-temperature strength when the L-drilling time is 4 hours.

FIG. 3 shows that at least 0.5 hours of aging treatment time is required, and that 8 hours is sufficient. FIG. 4 shows that the peak value of high-temperature strength is obtained when the relationship between the area reduction rate due to area reduction before aging treatment and the aging temperature is expressed by the above-mentioned formula.

Similarly, data obtained at other test temperatures showed that under the above conditions, heat resistance strength comparable to that obtained by conventional aging treatment was obtained.

Next, the reasons for limiting the component composition (weight ratio) of the heat-resistant metal material used in this invention will be explained.

Setting the Ni content in the material components to 45 to 60% is 45%.
If it is less than 60%, it is insufficient to obtain the desired amount of precipitated phase, and if it exceeds 60%, it is excessive and economically unfavorable.

If Cr is less than 15%, sufficient high temperature oxidation resistance cannot be obtained.
Also, if it exceeds 25%, the workability will decrease, so 15 to 25%
% is appropriate.

If the amount of +1 is less than 3%, the contribution to precipitation strengthening due to positive addition is low, and if it exceeds 7%, it is economically unfavorable.

The ratio is necessary as a grain boundary strengthening element, but if it is less than 2%, the effect is low, and in consideration of economic efficiency, 2 to 5% is appropriate.

N is effective as an element constituting the precipitate phase, but addition of more than 1% is not preferable because processability deteriorates. 0 again,
If it is less than 1%, the effect is weak.

■ is also effective as a constituent element of the precipitate phase, but its Φ is 1
．． If it exceeds 5%, high temperature oxidation resistance decreases, which is not preferable. If it is less than 0.1%, the effect will be weak.

Further, C is harmful other than contributing to grain boundary strengthening by combining with carbon, and therefore, addition of 0.1% or more is not preferable because it greatly reduces heat resistance strength.

<Example> Hereinafter, this invention will be explained in detail with reference to Examples.

Prepare a wire with the composition shown in Table 1 as a material, and 2.8
0 rmφ, 1.98 #Iφ, 1.61 darknessφ, 1.4
Adjust the wire diameter to four sizes in order of φ, then 10
After heating and holding in an H2 gas atmosphere at 50°C for 3 minutes, the wires were rapidly cooled to room temperature and then wire-drawn to 1.25 sφ, followed by solution treatment and then 20% and 40%, respectively.
, 60%, and 80% of the area were cold worked. Then, four types of samples with the same cross-sectional size of 1.25 aφ but different cross-sectional reduction ratios were prepared.

Each of these samples was subjected to an aging treatment for 4 hours at the temperatures shown below. FIG. 1 shows a schematic diagram of the manufacturing process of this invention.

For comparison, a sample subjected to aging treatment according to the conventional manufacturing process shown in FIG. 2 was also prepared.

Tensile tests were conducted on the samples obtained above using the method of the present invention and the conventional method at test temperatures of 500°C and 700°C. The results are shown in Figure 5.

This figure proves that the simple aging treatment of the present invention can provide a heat resistance strength comparable to that obtained by the conventional method.

<Effects of the Invention> As explained above, according to the method of the present invention, a 1N&ll-added N1-base alloy material having excellent heat resistance can be obtained by a simpler manufacturing method than ever before, and moreover, it can be produced using an existing installation surface. It was recognized that efficient production is possible.

Therefore, it has the great effect of eliminating price constraints and expanding the market scale.

[Brief explanation of the drawing]

FIG. 1 shows the statute of limitations 5[! Figure 2 is a schematic diagram showing an example of the L-treatment process. Figure 2 is a schematic diagram showing the aging treatment process of the conventional method. Figure 3 is a diagram showing the relationship between aging time, aging temperature, and high-temperature strength when the area reduction rate is specified. , Fig. 4 is a chart showing the relationship between cross-section reduction rate, aging temperature and high-temperature strength when aging treatment time is specified, and Fig. 5 is a chart comparing high-temperature strength of metal materials according to the method of this invention and the conventional method. . r---7゜1. 1, -, :l l l・□゛Applicant's agent Patent attorney Kazu 1) Showa Uni No. 114 Figure 2 (-ZSd+&)OFCX4Hr 7
2 (FCX8Hr4\Inventor Buddha
#Toho No. 4 Figure 3 S Hi1 @ Poetry @ (Hrs,) No. 514 Section η, Shao Mu (・mu)

Claims (1)

[Claims] Weight ratio: 45 to 60% Ni, 15 to 25% Cr, Na+
A heat-resistant metal material containing 3 to 7% Ta and 2 to 5% Mo, with the unavoidably mixed C being limited to less than 0.1%, and the remainder consisting of Fe and unavoidable impurities, or
A heat-resistant metal material containing one or two of 0.1-1.0% Ti and 0.1-1.5% Ti is solution-treated at 900-1250°C, resulting in a 10-80% cross-section reduction. Then, the following formula t=-2.5d+C (where t: aging treatment temperature, d: area reduction rate due to cold working before aging treatment, 10 to 80, C: 770 to 8
A method for producing a heat-resistant metal material, characterized in that aging treatment is performed at a temperature in the range of 0.5 to 8 hours (a constant of 20).