JP7081096B2 - Precipitation hardening Ni alloy - Google Patents

Description

The present invention relates to a precipitation hardening type high Ni heat resistant alloy in which one or more of the intermetallic compound particles of Al, Ti, and Nb are dispersed and precipitated in the Ni matrix to increase the high temperature mechanical strength, and particularly high mechanical strength. The present invention relates to a precipitation hardening type high Ni heat resistant alloy having excellent machinability.

Precipitation hardening type high Ni heat resistant alloys in which intermetallic compounds are finely precipitated in the Ni matrix are known as alloy materials for heat resistant parts that require high temperature mechanical strength such as automobile engine valves and turbine wheels for thermal power generation. ing. Such a high Ni heat resistant alloy contains precipitate-forming elements such as Al, Ti, and Nb that form an intermetallic compound with Ni in the component composition, but these elements have a strong bonding force with C and are carbides. Easy to form. Therefore, in the high Ni heat resistant alloy containing C, excellent high temperature mechanical strength due to the intermetallic compound can be obtained, but there is a problem that the machinability (machinability) is lowered due to the precipitated carbide.

In order to improve the machinability of such high Ni heat-resistant alloys, the composition of alloy components including carbon and precipitate-forming elements is strictly controlled and adjusted using a vacuum melting furnace, a remelting furnace, and the like. There is. Further, control of aging heat treatment for controlling the precipitation state of precipitates has also been proposed.

For example, in Patent Document 1, a high Ni heat-resistant alloy containing about 14 to 25% Cr, and a precipitation-hardening Ni-based heat-resistant alloy for hot dies containing Al, Ti, and Nb, contains C. It is disclosed that the machinability can be improved by controlling the weight% to 0.03% or less and suppressing the precipitation of carbides. Here, among high Ni heat-resistant alloys, the poor machinability of alloys having a component composition that precipitates intermetallic compounds called γ'phases and γ'phases in addition to the γ phase is generally described. It is said that the cause of such low machinability is the hardness of the fine particles made of the intermetallic compound which is the reinforcing phase, but the influence of the primary carbides precipitated during the solidification process during casting of the alloy is also large. The amount of C is controlled in order to suppress the precipitation of the primary carbide.

Further, in Patent Document 2, as in Patent Document 1, in a high Ni heat-resistant alloy containing about 14 to 25% Cr, the precipitated fine primary carbide is dissolved in a matrix by soaking heat treatment to improve machinability. The method is disclosed. The soaking heat treatment is, for example, a heat treatment in which the alloy is held at a relatively high temperature range for a long time of 10 to 40 hours with respect to the melting point of the alloy at 1100 to 1300 ° C. It states that it can be reduced to 100 or less.

Japanese Unexamined Patent Publication No. 2009-167499 Japanese Unexamined Patent Publication No. 2009-167500

As described above, in the soaking heat treatment, the alloy is exposed to a temperature range relatively high with respect to its melting point for a long time, so that the mechanical strength may decrease depending on the alloy. In addition, some carbides in the alloy could not be sufficiently dissolved in the matrix even by soaking heat treatment, and the machinability was not improved in some cases.

The present invention has been made in view of the above circumstances, and an object thereof is to disperse and precipitate one or more of the intermetallic compound particles of Al, Ti, and Nb in the Ni matrix. It is an object of the present invention to provide a precipitation hardening type high Ni heat resistant alloy which is a high Ni heat resistant alloy whose high temperature mechanical strength is increased and which can obtain high machinability without soaking heat treatment.

The present inventor has a precipitation-hardened high Ni that has a specific component composition in which one or more of the intermetallic compound particles of Al, Ti, and Nb are dispersed and precipitated in the Ni matrix to increase the high-temperature mechanical strength. It was found that in heat-resistant alloys, the influence of nitrides has a greater effect on machinability than carbides. Where there is a limit to reducing the amount of carbon as an unavoidable impurity, we will develop an alloy manufacturing method that can reduce nitrides and / or carbonitrides (hereinafter, simply referred to as "carbonitrides"). At the same time, a new precipitation-hardening high-Ni heat-resistant alloy with excellent machinability has been obtained.

That is, the high Ni heat-resistant alloy according to the present invention has Cr: 14 to 25%, Mo: 15% or less, Co: 15% or less, Cu: 5% or less, Al and Ti of 4% or less, and Nb in mass%. Has a component composition of 6% or less, Al + Ti + Nb of 1.0% or more, inevitable impurities containing at least C and N, and the balance of Ni, C: 0.01% or less, and carbonitride. The amount of N fixed as an object is 100 or less at the Michelin point determined from the inclusions extracted by the evaluation method based on ASTM-E45.

According to such an invention, the produced carbonitride is not attempted to be solid-solved in the matrix phase, but suppresses the formation of fine carbonitride itself, and the grain boundaries are melted and the crystal grains are coarsened. It is not necessary to undergo soaking heat treatment at a high temperature, which may impair the mechanical strength due to such factors, and high machinability can be obtained.

The invention described above may be characterized by further containing Fe: 15 to 30%. According to such an invention, a part of Ni can be replaced with cheaper Fe to obtain a high Ni heat resistant alloy having excellent alloy cost and high machinability.

The invention described above may be characterized in that the Michelin point is linearly proportional to C + 4.5N in the component composition. Further, it may be characterized in that N: 0.0050% or less. According to such an invention, high machinability can be obtained efficiently by reducing the amount of N.

The invention described above may be characterized by further containing P: 0.005 to 0.010%. According to such an invention, creep resistance can be improved particularly in high temperature mechanical strength.

It is a list of examples of the component composition of the high Ni heat resistant alloy according to this invention. It is a flow diagram which shows the process of the manufacturing method of the high Ni heat-resistant alloy by this invention. It is a perspective view which shows the shot blast processing. It is a schematic diagram which shows an example of a melting process. It is a table which shows the measurement result of the content of C and N and the degree of cleaning of a high Ni heat resistant alloy (Example 1). It is a table which shows the measurement result of the content of C and N and the degree of cleaning of a high Ni heat resistant alloy (Example 2, comparative example 1). It is a photograph which shows the cross section of the alloy 1 which has different total contents of C and N. It is a graph which shows the relationship between the total content of C and N in the high Ni heat resistant alloy by this invention, and the degree of cleaning. It is a graph which shows the relationship between the content of P and the creep characteristic. It is a photograph of the tip of the tool after the turning test. It is a list of component compositions for alloy examples to which this manufacturing process can be applied.

A high Ni heat resistant alloy as one example according to the present invention will be described with reference to FIGS. 1 to 11.

As will be described later, the high-Ni heat-resistant alloy targeted here is a precipitation-hardening alloy in which fine intermetallic compounds called γ'phase and γ'phase are dispersed and precipitated in the γ phase, which is the parent phase of Ni. It is a precipitation-hardening type high Ni heat-resistant alloy containing precipitate-forming elements of Al, Ti, and Nb.

That is, as shown in FIG. 1, the high Ni heat-resistant alloy requires the addition of any one or more of Al, Ti, and Nb that precipitate an intermetallic compound with Ni, and Fe, Cr, and Mo in addition to the addition. , Cu, Co, etc. are added in a predetermined range to the alloy containing Ni as a main component. Here, the "high Ni heat resistant alloy" is not only an alloy containing 50% or more by mass of Ni (see Example 1 in FIG. 1), but also an alloy containing approximately 30% by mass or more and less than 50% of Ni (see Example 1 in FIG. 1). It shall mean both of (see Example 2 in FIG. 1).

As shown in the alloys 1 to 4 of FIG. 1, the high Ni heat-resistant alloys of Examples 1 and 2 have Cr: 14 to 25%, Mo: 15% or less, Co: 15% or less in mass%. Cu: 5% or less, Al and Ti are 4% or less, Nb is 6% or less, Al + Ti + Nb is 1.0% or more, and the balance is Ni. Here, the unavoidable impurities including at least C and N are contained, the C of the unavoidable impurities is 0.01% or less, and the N fixed as the carbonitride is set to 100 at the Michelin point described later. By setting the amount to less than or equal to the amount, one or more of the intermetallic compound particles of Al, Ti, and Nb are dispersed and precipitated in the Ni matrix to increase the high-temperature mechanical strength. At this time, for example, as shown in the alloy 1 and the alloy 4 in FIG. 1, 15 to 30% Fe may be further contained.

Next, in the above-mentioned high Ni heat-resistant alloy, the reason for limiting the component range of each additive element will be briefly described below.

Al and Ti form a γ'phase, which is an intermetallic compound with Ni, and are finely dispersed and precipitated in the parent phase γ to increase the high temperature strength. In addition, Nb also forms a γ "phase, which is an intermetallic compound with Ni, and finely disperses and precipitates in the matrix γ to increase the high-temperature strength. On the other hand, Al, Ti, and Nb form carbides and nitrides. Highly capable, especially very fine carbonitrides formed after melting do not have a significant effect on high temperature strength, but they rapidly wear the bite blade during cutting and reduce machinability. In consideration of these, Al and Ti are defined as 4% or less, Nb is 6% or less, and Al + Ti + Nb is defined as 1.0% or more in mass%.

Cr enhances oxidation resistance, corrosion resistance, and high-temperature strength, but on the other hand, when it is excessively contained, the content of Ni in the alloy is relatively lowered, and the high-temperature strength is lowered. In consideration of these, Cr is set in the range of 14 to 25% in mass%.

Mo dissolves in the matrix to strengthen the matrix. In consideration of these, Mo is set to be in the range of 15% or less, preferably in the range of 0.1 to 10% in terms of mass%.

Cu enhances the corrosion resistance to chloride ions, but if the content is too large, it affects the high temperature strength. In consideration of these, when Cu is added, the mass% is within the range of 5% or less.

Co dissolves in the matrix to strengthen the matrix. Further, the precipitation amount of the intermetallic compound of Ni and Al, Ti, Nb is increased, and as a result, the high temperature strength of the alloy is increased. In consideration of these, when Co is added, the mass% is within the range of 15% or less.

Fe replaces Ni in the γ'phase. Therefore, the amount of Ni can be reduced and the cost of the alloy can be reduced. On the other hand, if it is contained in an excessive amount, the amount of Ni is reduced and the required high-temperature strength cannot be obtained. In consideration of these, when Fe is added, the mass% is in the range of 15 to 30%.

An embodiment of the above-mentioned manufacturing process for a high Ni heat-resistant alloy is shown with reference to FIGS. 2 to 4.

The melting step S100 melts various high Ni heat-resistant alloys having a component composition as shown in FIG. 1 while controlling the upper limit of unavoidable impurities (here, C and N). Here, in the melting step S100, generally, a waste material (scrap raw material) having a component composition similar to that shown in FIG. 1 and a component adjusting alloy are combined and melted. The "waste material" is, for example, a waste material of a product that has reached the end of its life distributed in the scrap market, an alloy material, or a waste material whose composition is controlled in-house when a new product is manufactured. means. Of the waste materials, the latter waste material is referred to as a "return material", and the return material is preferable in terms of controlling the components including unavoidable impurities.

First, waste materials and alloys for raw materials such as Fe—Nb, Fe—Cr, and Ni are prepared as raw materials (raw material preparation step: S101). At this time, the raw material alloy is prepared with a low content of C and N, and includes a removing step of processing and removing the film on the surface of the waste material (film removing step: S101a). As described above, for the production of various high Ni heat resistant alloys having the component composition as shown in FIG. 1, the alloy having a component composition close to this has carbides, nitrides or carbonitrides on the surface together with an oxide film. A compound film containing the compound is formed, and in particular, by containing the precipitate-forming elements of Al, Ti, and Nb, nitrides or carbides are likely to be contained, and the amount of N in the alloy as a whole tends to be increased. By removing these films from the surface of the waste material, impurities that are sources of carbon C and nitrogen N are removed before melting in the melting furnace in the subsequent melting step S102, and the final high Ni is produced. The C and N contents of the heat-resistant alloy can be reduced.

In the film removing step S101a, as shown in FIG. 3, "shot blasting" can be exemplified. In the shot blasting process, for example, a blast flow 14 containing hard fine particles is jetted from an injection mechanism 12 such as a nozzle onto the surface of the waste material 10, and the fine particles are made to collide with the injection surface 16 on the surface to mechanically form the compound film 10b on the surface. I will remove it. Then, the injection mechanism 12 is moved along the waste material 10 to continuously form the surface 10a after removal. In recent years, high Ni heat resistant alloys have also been used for members having complicated shapes, for example, drills for oil drilling. Even if the waste material 10 has such a complicated shape, it is excellent in workability in the shot blasting process in which it is not necessary to manufacture a jig or the like so as to adapt to the shape. Any technique for processing and removing the compound film from the surface of the waste material can also be applied.

Subsequently, the waste material 10 whose surface has been processed and removed and the alloy for raw materials controlled to low C and low N are heated to a predetermined temperature and melted in a vacuum melting furnace (melting step: S102). Then, the alloy component is adjusted by adding additional additive elements as needed (component adjusting step: S103). Then, the molten metal whose composition has been adjusted is cast into a mold having a predetermined shape, and ingots having various shapes are cast (ingot manufacturing step: S104).

Specifically, as shown in FIG. 4, the waste material 10 from which the compound film on the surface has been removed in the film removing step S101a and the raw material alloy 11 are put together into the melting chamber 17 of the vacuum melting furnace (FIG. 4 (a). ), Heat to a predetermined temperature and melt (see FIG. 4 (b)). After that, the molten metal M whose composition has been adjusted is cast into a mold 18 to cast ingots 20 having various shapes (see FIG. 4 (c)).

Further, soaking heat treatment can be appropriately performed as long as heat damage is allowed so as to further suppress the residual carbides and nitrides in the ingot. When the amount of C is extremely low, which is 0.01% or less in mass%, the precipitation of carbides is very small in the alloy block after melting, so the amount of C is more than 0.01%. It is desirable to apply the soaking heat treatment process only.

Then, the ingot is processed into a final product through forging, cutting, etc., and appropriately after secondary melting. The high Ni heat-resistant alloy manufactured by such a manufacturing process suppresses the precipitation of carbides and nitrides in the ingot by carrying out a film removing step of processing and removing the surface of the waste material at the stage of melting the raw material, resulting in this. As a result, the machinability of high Ni heat resistant alloys can be improved.

The above-mentioned manufacturing process of the high Ni heat-resistant alloy can be mentioned as the following features.

It is a method for producing a precipitation-hardening Ni-based heat-resistant alloy including at least a melting step, and the melting step includes a preparation step of preparing a raw material containing a waste material made of a Ni-based alloy and melting the raw material in a furnace. It is characterized by including a melting step and a component adjusting step of adjusting the alloy component of the alloy molten metal in the furnace, and the preparatory step includes a removing step of processing and removing the surface of the waste material.

The waste material may be characterized in that it is a Ni-based alloy containing at least one of Al, Ti, and Nb, and containing more than 1% in total mass% of these.

The removal step may be characterized in that it is a step of processing and removing a compound film containing a nitride and / or a carbonitride on the surface of the waste material.

The removal step may be characterized in that the surface of the waste material is shot blasted.

It may be characterized by including a soaking heat treatment step of dissolving the produced compound particles after the melting step.

The precipitation-hardened Ni-based heat-resistant alloy may be characterized by having a component composition in which N is larger than C in terms of the mass equivalent of carbides and / or nitrides.

Next, a specific example of manufacturing a high Ni heat resistant alloy by the above-mentioned manufacturing process of a high Ni heat resistant alloy will be described below.

First, a high Ni heat-resistant alloy return material was used as a raw material. Here, the target chemical composition of the final alloy is shown in the alloys 1 to 5 in FIG. The alloy 5 is an alloy containing about 44% by mass of Ni but not Cr, like the alloy 4, and was used as a comparative example.

The return material and the alloy for raw materials controlled to low C and low N were put into a vacuum induction melting furnace as raw materials and heated to melt them. Then, an alloy for adjusting the chemical composition range of the above-mentioned alloys 1 to 5 was placed in the melting furnace, the composition was adjusted, and the ingot was cast into a mold. Subsequently, it was hot forged at a temperature of about 1100 ° C. to form a round bar, and heat-treated at a temperature of 1050 ° C. for 30 minutes to produce a billet.

Regarding the test piece cut out from the billet, the contents of carbon C and nitrogen N were measured, and "cleanliness" based on Michelin points was measured as an index of the machinability. The results are shown in FIGS. 5 and 6, and FIG. 7 shows a cross-sectional photograph of the alloy 1 for measuring the Michelin point. As shown in FIGS. 5 and 6, the test No. In 1, 2, 4, 7, 8, 10, 11, 13, and 14, the return material collected as a raw material was subjected to a surface film removing step by shot blasting before melting. In shot blasting, steel particles having an average particle size of 0.8 mm and a hardness of HRC 40 to 50 were sprayed onto the surface of the return material.

Here, the "cleanliness" is defined by a "Michelin point" indicating the degree of non-metal inclusions such as carbides and nitrides contained in the alloy structure. Here, the "Michelin point" is an index for evaluating inclusions by the "Michelin method" based on ASTM-E45. First, by observing the cross-sectional structure having a test area of 60.5 mm ² at a magnification of 400, the size of non-metal inclusions having an aspect ratio of 2 or less and a width of 5 μm or more dispersed in the structure is measured. do. Then, regarding the measured inclusions, those having a size (length) of 5 μm or more and less than 10 μm have a coefficient of 1, those having a size (length) of 10 μm or more and less than 20 μm have a coefficient of 5, and those having a size (length) of 20 μm or more have a coefficient of 10. Multiply the number and use the sum of these as the Michelin point value. Therefore, the smaller the Michelin point value, the smaller the inclusions in the observation field, and the higher the degree of cleaning, and the larger the Michelin point value, the more inclusions, and the lower the degree of cleaning.

<Example 1>
As shown in FIG. 5, in an alloy containing 50% or more of Ni by mass%, in the three test pieces with respect to alloy 1, the contents of carbon C and nitrogen N are each by mass%, and C: 0.0030 to 0. The range was 0250%, N: 0.0030 to 0.0087%, and the cleanliness at this time was 40 to 300. Similarly, the three test pieces for alloy 2 contained carbon C and nitrogen N. The amounts were in mass%, C: 0.0020 to 0.0310%, N: 0.0029 to 0.0112%, and the cleanliness was 20 to 400. Further, in the three test pieces for the alloy 3, the contents of carbon C and nitrogen N are in the range of C: 0.0040 to 0.0600% and N: 0.0050%, respectively, in mass%, and the cleanliness is It was 20 to 150.

<Example 2>
As shown in FIG. 6, in an alloy containing approximately 30% by mass or more and less than 50% of Ni, in the three test pieces with respect to the alloy 4, the contents of carbon C and nitrogen N are each by mass%, and C: 0.0050. The range was from 0.0300% and N: 0.0030 to 0.0070%, and the cleanliness at this time was 10 to 130.

<Comparative Example 1>
Similarly, in the alloy containing only about 30% by mass or more and less than 50% of Ni, but not containing Cr, in the four test pieces with respect to the alloy 5, the contents of carbon C and nitrogen N are C in mass%, respectively. : 0.0020 to 0.0080%, N: 0.0010 to 0.0024%, and the cleanliness was 50 to 500.

As shown in FIGS. 5 and 6, the high Ni heat-resistant alloy according to the present embodiment has C: 0.01% by mass or less, N: by removing the compound film formed on the surface of the waste material in the melting process. It was found that the Michelin point determined from the inclusions extracted by the evaluation method based on ASTM-E45 can be suppressed to 100 or less for N fixed as a carbonitride while making it 0.0050% by mass or less. .. Further, in the data shown in FIGS. 5 and 6, when the contents of C and N and the cleanliness based on the Michelin point value are compared, the total value X (X) obtained by totaling C: N at a ratio of 1: 4.5. = C + 4.5N) and cleanliness were found to be almost proportional.

That is, as shown in FIG. 8, the horizontal axis represents the value (C + 4.5N) depending on the carbon C and nitrogen N contents of the high Ni heat-resistant alloy, and the vertical axis represents the cleanliness based on the Michelin point. It can be seen that all of the alloys 1 to 5 have a substantially proportional relationship between the total content of (C + 4.5N) and the Michelin point value. This makes it possible to predict the Michelin point value of the high Ni heat resistant alloy by controlling the total content (C + 4.5N) of carbon C and nitrogen N contained in the high Ni heat resistant alloy to be manufactured. Become. However, in the alloy 5, the amount of change in the Michelin point value with respect to the amount of change in the (C + 4.5N) value is large, and the accuracy in predicting the Michelin point value is lower than that in the alloys 1 to 4.

Further, the high cleanliness of the high Ni heat-resistant alloy (that is, the small Michelin point value) means that the inclusions contained in the structure are small. As described above, the high Ni heat resistant alloy having high cleanliness has high machinability. Therefore, a high Ni heat resistant alloy that achieves both high high-temperature strength and machinability by removing the compound film such as carbides and nitrides in the melting process and suppressing the X value within the above-mentioned component range. Can be obtained.

For example, by determining the X value of the alloys 1 to 4 so that the cleanliness (Michelin point value) shown in FIG. 8 is 100 or less, the high Ni heat resistant alloy produced has good machinability. Can be obtained.

<Example 3>
FIG. 9 shows the results of a creep test using a test piece in which the content of P with respect to the above alloy 1 was changed to 0.003%, 0.005%, 0.010%, and 0.017% in mass%. show. In the creep test, the temperature was 649 ° C. and the load was 689 MPa with stress.

As shown in the figure, increasing the content of P tended to improve both the rupture time and the elongation as creep characteristics. Further, even in the test piece in which the content of P with respect to the alloy 4 described above was changed, the creep characteristics were similarly improved by containing a small amount of P. That is, in the above-mentioned high Ni heat-resistant alloy, from the viewpoint of high-temperature creep characteristics, it is preferable to contain P within a range that does not impair hot workability and manufacturability, and the content thereof is 0.005 to 0.010 mass. It is in the range of%.

<Turning test>
FIG. 10 shows a photograph of the tip of the tool when a turning test using a cemented carbide tool was performed on the billet of the alloy 2 described above. Here, the tip of the carbide tool 11 minutes after the start of the turning test is shown. The conditions for the turning test were a cutting speed of 50 m / min, a feed rate of 0.4 mm / rev, and a cutting depth of 2.0 mm.

First, as shown in FIG. 10A, in the billet manufactured by the conventional manufacturing method in which the waste material contained in the raw material is not shotblasted and is melted as it is, the tip of the tool is shown by the white arrow in the photograph. Was heavily worn.

On the other hand, as shown in FIG. 10B, in the billet manufactured by the above-mentioned manufacturing process for removing the compound film of the waste material, the wear of the cemented carbide tool is significantly reduced as shown by the white arrow in the photograph. It can be confirmed that there is. That is, the result was obtained that the high Ni heat-resistant alloy manufactured by the manufacturing process according to this example was superior in machinability to the same cemented carbide tool.

In addition, FIG. 11 lists alloys A to N as examples of high Ni heat-resistant alloys to which the above-mentioned manufacturing process can be applied, and shows the chemical components that are the final targets of each. It was confirmed in the same turning test as above that good machinability can be obtained even with these alloys. In addition, in the case of an alloy containing approximately 30% by mass or more of Ni, the same effect of improving machinability in the same manufacturing process can be obtained. Therefore, the high Ni heat resistant alloy referred to here includes an alloy containing approximately 30% by mass or more of Ni. It shall include.

By the way, in the conventional manufacturing method as described above, it is difficult to reduce the N content of the obtained ingot to 100 ppm or less even if the treatment time of the degassing treatment of the vacuum induction melting furnace is lengthened. On the other hand, the N content of the ingot obtained by the above-mentioned production process was 60 ppm or less, and the same N content was maintained in the billet. Here, by appropriately selecting the chemical composition of the high Ni heat-resistant alloy and the heat treatment conditions, the N content can be reduced to 50 ppm or less, preferably 40 ppm or less, the wear of the cemented carbide can be further reduced, and the work can be performed. It was also found that it could enhance sex.

Here, the machinability has been improved by reducing the amount of C in the past. On the other hand, as shown in the above-mentioned turning test, it was confirmed that the amount of N also greatly affects the machinability. Furthermore, when the amount of carbides and nitrides that affect machinability is obtained by microscopic observation of the alloy cross section, the amount of carbides and nitrides is reduced by the same amount of N than when C is reduced by a predetermined amount. It was also confirmed that there is a tendency to significantly reduce. This tendency was the same in all of the precipitation hardening type high Ni heat resistant alloys described above. That is, in the case of a high Ni heat-resistant alloy having a component composition having a component composition of N larger than C in terms of the produced mass equivalent of carbides and / or nitrides, the machinability can be effectively improved by applying the above-mentioned production process. It is.

Although typical examples of the present invention have been described above, the present invention is not necessarily limited to these, and those skilled in the art will not deviate from the gist of the present invention or the scope of the attached claims. , Various alternative and modified examples will be found.

10 Waste material 10b Compound film 12 Injection mechanism 14 Blast flow 16 Injection surface

Claims (3)

By mass%,
Cr: 14 to 25%,
P: 0.005 to 0.010%,
Mo: 15% or less,
Co: 15% or less,
Cu: 5% or less,
It has a component composition in which Al and Ti are 4% or less, Nb is 6% or less, Al + Ti + Nb is 1.0% or more, and unavoidable impurities including at least C and N and the balance Ni are used.
Michelin determined from inclusions extracted by an evaluation method based on ASTM-E45 for N fixed as carbonitride while containing Ni: 30% or more and C: 0.01% or less. A precipitation hardening Ni alloy characterized by an amount of 100 or less at the point. The precipitation hardening Ni alloy according to claim 1, further comprising Fe: 15 to 30%. N: The precipitation hardening Ni alloy according to claim 1 or 2 , wherein the content is 0.0050% or less.

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