JPS59179752A - Heat resistant co base alloy - Google Patents

Abstract

PURPOSE:To obtain a heat resistant Co base alloy having superior oxidation resistance and strength at high temp. and superior resistance to erosion due to molten glass by adding specified elements to Co as an essential component. CONSTITUTION:This heat resistant Co alloy consists of 0.05-0.6% C, 0.1-2% Si, 18-24% Cr, 10-20% W, 18-24% Ni, 0.5-5% Hf and the balance Co. The alloy may further contain 0.1-2% Mn and/or 0.005-0.1% rare earth element. The alloy has superior oxidation resistance and strength at high temp. and high resistance to erosion due to molten glass, and it is suitable for use as the material of a spinner for forming glass fiber.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Co-based heat-resistant alloy that has particularly excellent resistance to erosion of molten glass and is therefore suitable for use in manufacturing spinners for forming glass fibers.

Generally, glass fibers are prepared by charging molten glass heated to about K100°C in a spinner, and using this spinner f170
It is formed by rotating at a high speed of about 0 r, p, m, and ejecting molten glass by centrifugal force from a large number of pores drilled radially along the side wall of the spinner. Therefore, the spinner is required to have high-temperature oxidation resistance, high-temperature strength, particularly high-temperature creep rupture strength, and molten glass erosion resistance.

Conventionally, as a typical alloy used for manufacturing spinners for forming glass fibers, 28% Cr-13%N (by weight) has been used.
There is a Co-based heat-resistant alloy having a composition of i-10%W-1,5%Ta-co, but this conventional c.

The base heat-resistant alloy has particularly insufficient molten glass erosion resistance, so that the pore diameter of the spinner side wall becomes larger than the allowable limit at a relatively early stage, leading to the end of its service life.

Therefore, from the above-mentioned viewpoints, the present inventors conducted research to develop an alloy with high-temperature oxidation resistance, high-temperature strength (high-temperature creep rupture strength), and molten glass erosion resistance. In weight%, C: 0.05-0.6%
, Si: 0.1-2%, W ° 10-20%, Ni: 18-24%, Hf: 0.5-5%, and if necessary, Mn: 0.1-2%. %, Rare earth element: 0.005 to 0.1, Co-based heat-resistant alloy containing one or both of the following, with the remainder consisting of Co and unavoidable impurities:
This Co-based heat-resistant alloy has not only excellent high-temperature oxidation resistance and high-temperature strength (high-temperature creep rupture strength), but also excellent molten glass erosion resistance. It has been found that when used in production, the resulting spinner exhibits excellent performance over an extremely long period of time.

This invention was made based on the above knowledge, and the reason why the component composition range was limited as described above will be explained below.

(a) C The C component includes Or, W, and H, in addition to solid solution in the base material.
It combines with f to form carbides, thereby strengthening the inside of grains and grain boundaries, improving high-temperature strength, and further improving weldability and castability, but its content is 0.05 If the content is less than 6%, the desired effect cannot be obtained, while if the content exceeds 6%, the toughness will deteriorate.
It was set at 0.6%.

(b) In addition to having a deoxidizing effect, the 5i Si component also has the effect of improving the fluidity of the molten metal and further improving the high-temperature oxidation resistance.
If the content is less than 0.1%, the desired effect cannot be obtained, while if the content exceeds 2%, the toughness and weldability will deteriorate.
It was set at 0.1 to 2%.

(c) The 0rCir component is an essential austenite component for ensuring excellent high-temperature oxidation resistance, but if its content is less than 18%, it is difficult to ensure the desired high-temperature oxidation resistance. On the other hand, if the content exceeds 25 inches, the high temperature strength and toughness will drop sharply, so the content was set at 18 to 25 inches.

(d) w The W component combines with C to form MC type carbide, which is a high melting point carbide, while suppressing the formation of low melting point carbides of M703 type and M23C6 type, thereby improving high temperature strength, It dissolves in solid solution in the austenite matrix and has the effect of strengthening it, but if the content is less than 1%, the desired effect cannot be obtained, while if the content exceeds 20%, the high temperature oxidation resistance Not only will the toughness deteriorate rapidly, but also intermetallic compounds such as σ phase, which cause deterioration of toughness, will be formed, so the content should be increased by 10 to 2.
It was set as 0chi.

(e) The Ni N1 component has the effect of improving high-temperature strength in coexistence with Or, further forming an austenite matrix, stabilizing it well, and improving workability, but when its content is 18 If the content is less than 24%'e, the desired effect cannot be obtained, while if the content exceeds 24%'e, the high temperature oxidation resistance will deteriorate.
%.

(fl Hf The Hf component does not form MC type or M7C3 type eutectic carbide, but forms MC type primary carbide, which is a high melting point carbide, to improve high temperature oxidation resistance and high temperature strength, Furthermore, it has the effect of further improving the erosion resistance of molten glass, but if the content is less than 0.5%, the desired effect cannot be obtained, while if it is contained in excess of 5%, the above effect is further enhanced. However, in consideration of economic efficiency, the content was set at 0.5 to 5%.

(g) Mn In addition to having a strong deoxidizing effect, the Mn component has the effect of solid-dissolving into the austenite matrix, stabilizing it, and improving toughness, so it is necessary when these properties are required. However, if the content is less than 0.1%, the desired effect cannot be obtained, while if the content exceeds 2%, the high temperature oxidation resistance tends to deteriorate. Therefore, the content 'i was determined to be 0.1 to 2 articles.

(h) Rare earth elements These components have the effect of further improving high-temperature oxidation resistance, especially when coexisting with Hf, so they may be included as necessary when particularly excellent high-temperature oxidation resistance is required. However, if the content is less than 0.005%, the desired effect cannot be obtained, while if the content exceeds 0.1%, castability and workability tend to deteriorate. Therefore, the content i was determined to be 0.005 to 0.1%.

Note that among the inevitable impurities in the CO-based heat-resistant alloy of the present invention, particularly regarding Fe, the alloy properties are not impaired in any way even if it is contained up to 3%. It may be actively included.

Next, the CO-based heat-resistant alloy of the present invention will be specifically explained using examples.

Examples CO-based heat-resistant alloys 1 to 21 of the present invention and comparative CO alloys having the compositions shown in Table 1 were prepared by a conventional melting method.
The base heat-resistant alloys 1 to 9 are melted and cast using the lost wax precision casting method. Parallel part outer diameter near throat φ x parallel part length 50 m
+ n Next, from this test piece, a creep-loveture test piece was cut out for the purpose of evaluating high-temperature strength, and using this test piece, the atmosphere: air, heating temperature opening: 1100°C, load response: 3.5 9
A creep rupture test was conducted under the conditions of /- to measure the rupture life.

In addition, a test piece with dimensions of diameter: 10 questions φ x height: 10wn was cut out from the chuck part of the test piece after the above-mentioned creep-loveture test, and using this test piece, the test piece was placed in the atmosphere at a temperature of:
After holding at 1100° C. for 10 hours, one cycle of descaling was performed, and a high temperature oxidation resistance test was conducted to measure the oxidation loss after 10 cycles.

Furthermore, for the purpose of evaluating the erosion resistance of molten glass, the immersion part dimensions were determined from the above test piece material as diameter: 6 mmφ x length: 1.
6. Cut out a test piece and heat the test piece at a temperature of 11
A molten glass immersion test was conducted in which the samples were immersed in molten glass at 20° C. for 120 hours, and the rate of corrosion loss after the test was measured.

These measurement results are also shown in Table 1.

From the results shown in Table 1, it can be seen that while the present invention's CO-based heat-resistant alloys have good heat resistance, as seen in Comparative Co-based heat-resistant alloys 1 to 9,
If the content of any of the constituent components (marked with * in Table 1) falls outside the scope of this invention, at least one of the above properties will be inferior. is clear.

As mentioned above, the CO-based heat-resistant alloy of the present invention has excellent high-temperature strength and high-temperature oxidation resistance, and is also excellent in molten glass erosion resistance, so it can be used especially for glass fibers that require these properties. When used in the production of molding spinners, it exhibits excellent performance over an extremely long period of time.

Applicant: 2 people other than Mitsubishi Metals Corporation Agent Tomi 1) Kazuo and 1 other person Continuation of page 1 ■Person Asahi Glass Co., Ltd. 1 Marunouchiguchi-chome, Chiyoda-ku, Tokyo number 2

Claims (4)

[Claims] (1) c: 0.05-0.6%, Si: 0.1
~2%, Cr: 18~24%, W: 10~20%, N118~24%, Hf: 0.5~5%, with the remainder consisting of CO and inevitable impurities (wt%) A Co-based heat-resistant alloy characterized by having the following. (2) C! : 0.05-0.6%, Sl 01
Contains ~2%, Or: 18~24%, W: 10~20%, Ni: 18~24φ, Hf:Q, 5~5%, and further contains Mn:Q, 1~2%. A CO-based heat-resistant alloy having a composition (weight %) with the remainder consisting of CO and unavoidable impurities. (3) c: 0.05-0.6%, 8i:Q, 1
~2%, Cr218-24%, W. 10-2
Composition (base weight %)'f: A CO-based heat-resistant alloy characterized by having. (4) O: 0.05-06cm, S10.1-2cm, Cr: 18-24%, W: 10-20%, Ni: 18-24%, Hf: 0.5-5%, and further contains Mn: 0.1 to 2%, rare earth elements: 0.005 to 0.1%, and the remainder is Co and unavoidable impurities (weight %). Co-based heat-resistant alloy.