JPH06240393A - Co base alloy excellent in high temperature strength - Google Patents

Abstract

PURPOSE:To provide a Co base allay particularly excellent in high temp. strength. CONSTITUTION:The Co base alloy has a compsn. contg., by weight, 0.1 to 1.2% C, 0.01 to 2% of one or more kinds of Si and Mn, 22 to 37% Cr, 5 to 15% Ni, 0.1 to 5% Hf and 0.1 to 3.5% Re and furthermore contg., at need, one or more kinds among the following (a) to (d) of (a) 0.1 to 12% of one or more kinds of Ta and Nb, (b) 0.1 to 10% of one or more kinds of W and Mo, (c) 0.005 to 0.1% of one or more kinds of B and Zr and (d) 0.005 to 0.1% of one or more kinds of rare earth elements including Y, and the balance Co 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 Co-based alloy which has excellent high temperature strength, high temperature oxidation resistance, high temperature fluid wear resistance and molten glass erosion resistance. is there.

[0002]

2. Description of the Related Art Conventionally, generally, for example, glass fibers are charged with molten glass heated to about 1000 ° C. in a spinner, and the spinner is rotated at a high speed at a rotation speed of about 1700 rpm to form a side wall of the spinner. It is well known that the molten glass is formed by ejecting the molten glass from a large number of pores radially formed in accordance with the centrifugal force. Therefore, the above-mentioned glass fiber molding spinner has high-temperature strength and high-temperature acid resistance. Since chemical conversion resistance and molten glass erosion resistance are required, for example, Japanese Patent Publication No.
Co-based alloys described in Japanese Patent Publication No. 3-30384 are used. Further, structural members such as turbine nozzles and vanes of a gas turbine are required to have high-temperature strength and high-temperature oxidation resistance as well as wear resistance to high-temperature fluids such as high-temperature combustion gas, and therefore have these characteristics. It is also known that, for example, the Co-based alloy described in Japanese Patent Publication No. 3-43813 is used.

[0003]

On the other hand, in recent years, for example, the progress of higher output of gas turbines and higher speed of glass fiber molding has been remarkable, and accordingly, structural members of these gas turbines and glass fiber molding have been accompanied. Spinners are required to have much higher high-temperature strength, and the conventional Co-based alloys that compose them are included.
Since many other Co-based alloys do not have sufficiently high temperature strength, they are currently used for a relatively short time during practical use under severer high temperature conditions.

[0004]

Therefore, the present inventors have
From the above-mentioned viewpoint, as a result of research to develop a Co-based alloy having particularly high strength at high temperature, C: 0.1 to 1.2% by weight% (hereinafter,% means% by weight) , Si
And one or two of Mn: 0.01 to 2%,
Cr: 22-37%, Ni: 5-15%, H
f: 0.1 to 5%, Re: 0.1 to 3.5%,
And (a) Ta and N, if necessary.
One or two of b: 0.1 to 12%, (b)
One or two of W and Mo: 0.1 to 10
%, (C) one or two of B and Zr:
0.005 to 0.1%, (d) one or more of rare earth elements including Y: 0.005 to 0.1%, (a) to
A Co-based alloy containing one or more of (d) and the balance being Co and inevitable impurities has excellent high-temperature strength, high-temperature oxidation resistance, and high-temperature fluid. It is also excellent in wear resistance and molten glass erosion resistance, so that when it is used for manufacturing structural members of gas turbines, glass fiber molding spinners, etc., it can be used under severe high temperature conditions. We obtained the results of research that demonstrated excellent performance over an extremely long period of time.

The present invention was made on the basis of the above-mentioned research results, and the reason why the component composition is limited as described above will be explained below. (A) C C component has a function of forming a solid solution in the matrix to strengthen it and form carbides to improve high temperature fluid wear resistance, but if the content is less than 0.1%, The desired high temperature fluid wear resistance cannot be ensured, while its content is 1.
If it exceeds 2%, rapid embrittlement will occur, so
Its content was set to 0.1 to 1.2%.

(B) Si and Mn These components are indispensable components for deoxidation of the molten alloy, and therefore if the content is less than 0.01%, the desired deoxidation effect cannot be secured. , While its content is 2
%, The alloy becomes brittle, so its content was set to 0.01 to 2%.

(C) Cr The Cr component has the action of forming carbides to improve the high temperature fluid wear resistance as described above and also has the action of forming a solid solution in the matrix to improve the high temperature oxidation resistance. If the content is less than 22%, the desired effect cannot be obtained, while if the content exceeds 37%, the high temperature strength and toughness will decrease, so the content is defined as 22 to 37%. It was

(D) Ni The Ni component, which forms a solid solution in the matrix and improves the oxidation resistance in the presence of Co and Cr, and also the high temperature strength, has a content of less than 5%. In that case, the desired improving effect on the above-mentioned action cannot be obtained, and even if the content exceeds 15%, the above-mentioned action is saturated and the further improving effect does not appear. Therefore, the content is set to 5 to 15%. Specified.

(E) The Hf Hf component has a function of forming a carbide to improve the high temperature fluid wear resistance and a solid solution in the matrix to improve the molten glass erosion resistance. If it is less than 0.1%, the desired effect of improving the above-mentioned action cannot be obtained, and if the content exceeds 5%, the toughness tends to decrease, so the content is defined as 0.1 to 5%. It was

(F) Re Re component has a function of forming a solid solution in the base material and remarkably improving high temperature strength in the coexistence with the Hf component, but if the content thereof is less than 0.1%, the desired and excellent results are obtained. High temperature strength cannot be ensured, and on the other hand, if the content exceeds 3.5%, the toughness decreases, so the content is set to 0.1 to 0.1%.
It was set at 3.5%.

(G) Ta and Nb These components act to form carbides to improve high temperature fluid wear resistance, and to form a solid solution in the matrix to improve high temperature oxidation resistance and molten glass erosion resistance. However, if the content is less than 0.1%, the desired effect cannot be obtained, while if the content exceeds 12%, the toughness decreases. Because
Its content was set to 0.1 to 12%.

(H) W and Mo These components have the action of forming carbides to improve the high temperature fluid wear resistance, and to form a solid solution in the matrix to improve the high temperature strength. However, if the content is less than 0.1%, the desired effect cannot be obtained, and if the content exceeds 10%, the high temperature oxidation resistance and toughness are deteriorated. Therefore, the content was determined to be 0.1 to 10%.

(I) B and Zr These components have the effect of strengthening the crystal grain boundaries and thus improving the high temperature strength, so they are contained as necessary, but their content is 0.005%. If it is less than 0.1%, the desired effect of improving high temperature strength cannot be obtained, and if the content exceeds 0.1%, the toughness tends to decrease. Therefore, the content is set to 0.005 to 0.1%. .

(J) Rare Earth Element Containing Y The rare earth element containing Y has an action of improving high temperature oxidation resistance, so it is contained as necessary, but if the content is less than 0.005%. The effect of improving high-temperature oxidation resistance is insufficient, and if the content exceeds 0.1%, the castability and workability will be impaired. Defined as%.

(K) Fe The Co-based alloy of the present invention may contain an Fe component as an unavoidable impurity.
Even if it is contained up to 4%, it does not have any adverse effect on the alloy characteristics, so in consideration of economy, it may be positively contained within the range of up to 4%.

[0016]

EXAMPLES Next, the Co-based alloy of the present invention will be specifically described by way of examples. The Co-based alloy of the present invention 1 having the component compositions shown in Tables 1 to 7, respectively, by the usual melting method.
~ 61 and comparative Co-based alloys 1 to 10 were melted respectively, and these molten alloys were subjected to the lost wax precision casting method, and the specimen materials for the creep rupture test (diameter: 12 mm x Length: 120
mm round bar), high temperature oxidation test specimen material for evaluating high temperature oxidation resistance (diameter: 12 mm x length: 120 mm round bar), high temperature fluid wear test for evaluating high temperature fluid wear resistance Test piece material (diameter: 12 mm x length: 120 mm round bar), and test piece material for molten glass nozzle ejection test (diameter: 35 mm x thickness: 5 mm disc) for evaluating resistance to molten glass erosion ).

The comparative Co-based alloys 1 to 10 are those in which the content of any one of the basic constituents (marked with * in Table 7) is out of the range of the present invention. is there. In the creep rupture test, a test piece having the dimensions of parallel part diameter: 6 mm x parallel part length: 32 mm x chuck (screw) part diameter: 12 mm x total length: 80 mm was cut out from the above material, and this test piece was cut. Use, atmosphere: in the air,
The heating temperature: 950 ° C., the load stress: 12 kg / mm ² , the breaking life (high temperature strength) was measured, and the elongation was measured for the purpose of evaluating the high temperature toughness.

In the high temperature oxidation test, a test piece having a size of 10 mm in diameter and 12 mm in height was cut out from the above material, and the test piece was held at a temperature of 1125 ° C. for 12 hours and then cooled. 1 cycle of descaling, 5
By repeating the cycle, the weight loss of the test piece after the test was measured, and the ratio (weight loss rate of the oxidation) to the weight of the test piece before the test was calculated.

The high temperature fluid wear test was conducted from the above materials using the diameter:
Kerosene combustion gas (temperature: 900 ° C) in which a test piece having a size of 10 mm x length: 100 mm was cut out, and alumina powder having an average particle diameter of 100 µm was blended at a rate of 5 g / min. Was set up in a pipe passing through at a flow rate of about 90 m / sec, and this state was maintained for 48 hours, and the wear depth of the fluid facing surface at the center of the test piece after the test was measured.

In the molten glass nozzle ejection test, the central portion of the above material was thinned to a thickness of 1 mm by cutting, a hole having a diameter of 0.5 mm was bored in this thinned portion, and the inner diameter was 20 mm.
As a bottom plate of a Co-based alloy crucible, and in the crucible, soda glass in which WC powder having an average particle diameter of 5 μm is mixed at a ratio of 3% by volume is melted in the air, and the molten glass is heated to 1050 ° C.
Test was conducted by applying a pressure of 3 atm to the molten glass from above the crucible in the state of being heated and held at, and ejecting the molten glass from the hole in the bottom plate of the crucible, and continuing the ejection of the molten glass for 48 hours. After that, the hole diameter was measured, and from this measurement result, the hole diameter change rate, that is, [(hole diameter after test)-(hole diameter before test)] / (hole diameter before test) x 100
% Was calculated. The results are shown in Tables 8-11.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

[0025]

[Table 5]

[0026]

[Table 6]

[0027]

[Table 7]

[0028]

[Table 8]

[0029]

[Table 9]

[0030]

[Table 10]

[0031]

[Table 11]

[0032]

From the results shown in Tables 1 to 11, the Co-based alloys 1 to 61 of the present invention all have remarkably excellent high temperature strength, high temperature toughness, high temperature oxidation resistance, and high temperature fluid wear resistance. , And also have excellent resistance to molten glass erosion, while, as seen in Comparative Co-based alloys 1 to 10, if the content of any one of the constituents is out of the range of the present invention, It is clear that at least one of the above properties will be inferior. As described above, the Co-based alloy of the present invention has particularly excellent high-temperature strength and excellent high-temperature oxidation resistance, high-temperature fluid wear resistance, and molten glass erosion resistance. Is required, for example, when used as a structural member of a gas turbine or a glass fiber molding spinner, industrially useful properties such as excellent performance for a long period of time even in practical use under more severe conditions. Have.

Claims (16)

[Claims] 1. By weight%, C: 0.1 to 1.2%, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, With the balance being Co and unavoidable impurities, and a Co-based alloy with excellent high-temperature strength. 2. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of Ta and Nb: 0.1 to 12
%, With the balance being Co and unavoidable impurities, and a Co-based alloy with excellent high-temperature strength. 3. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And 1 or 2 kinds of W and Mo: 0.1 to 10
%, With the balance being Co and unavoidable impurities, and a Co-based alloy with excellent high-temperature strength. 4. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of B and Zr: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 5. By weight%, C: 0.1 to 1.2%, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or more of rare earth elements including Y: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 6. In weight%, C: 0.1 to 1.2%, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of Ta and Nb: 0.1 to 12
%, One or two of W and Mo: 0.1 to 10
%, With the balance being Co and unavoidable impurities, and a Co-based alloy with excellent high-temperature strength. 7. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of Ta and Nb: 0.1 to 12
%, One or two of B and Zr: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 8. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of Ta and Nb: 0.1 to 12
%, One or more rare earth elements including Y: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 9. By weight%, C: 0.1 to 1.2%, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And 1 or 2 kinds of W and Mo: 0.1 to 10
%, One or two of B and Zr: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 10. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And 1 or 2 kinds of W and Mo: 0.1 to 10
%, One or more rare earth elements including Y: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 11. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of B and Zr: 0.005
0.1%, one or more kinds of rare earth elements including Y: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 12. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of Ta and Nb: 0.1 to 12
%, One or two of W and Mo: 0.1 to 10
%, One or two of B and Zr: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 13. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of Ta and Nb: 0.1 to 12
%, One or two of W and Mo: 0.1 to 10
%, One or more rare earth elements including Y: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 14. C: 0.1 to 1.2% by weight, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of Ta and Nb: 0.1 to 12
%, One or two of B and Zr: 0.005
0.1%, one or more kinds of rare earth elements including Y: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 15. By weight%, C: 0.1 to 1.2%, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And 1 or 2 kinds of W and Mo: 0.1 to 10
%, One or two of B and Zr: 0.005
0.1%, one or more kinds of rare earth elements including Y: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy. 16. In weight%, C: 0.1 to 1.2%, one or two of Si and Mn: 0.01 to 2
%, Cr: 22 to 37%, Ni: 5 to 15%, Hf: 0.1 to 5%, Re: 0.1 to 3.5.
%, And one or two of Ta and Nb: 0.1 to 12
%, One or two of W and Mo: 0.1 to 10
%, One or two of B and Zr: 0.005
0.1%, one or more kinds of rare earth elements including Y: 0.005
C having excellent high temperature strength, characterized in that it has a composition containing 0.1% and the balance being Co and unavoidable impurities.
o-based alloy.