Claims
- 1. A process of preparing an Fe-Cr-Ni-Al ferritic alloy having in its surface an aluminum oxide hot corrosion resistive scale, said process comprising the steps of:
- forming an alloy consisting essentially of by weight 25 to 35 percent chromium, 15 to 25 percent nickel; 4 to 8 percent aluminum, 0.05 to 1.0 percent at least one element selected from the group consisting of zirconium, hafnium, cerium, lanthanum, neodymium, gadolinium; not more than 0.1 percent of yttrium; and balance iron;
- exposing said alloy to hot oxidation environments at a first temperature of not less than 1000.degree. C. for an extended time in order to form in the surface thereof said aluminum oxide scale chiefly composed of alumina oxide;
- heating, immediately subsequent to said hot oxidation, said alloy to a temperature above said first temperature for a relatively short time period; and
- cooling said alloy to a room temperature.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1-289658 |
Nov 1989 |
JPX |
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Parent Case Info
This is a divisional of application Ser. No. 07/604,231 filed Oct. 19, 1990, now U.S. Pat. No. 5,089,223.
Foreign Referenced Citations (1)
Number |
Date |
Country |
57-39159 |
Mar 1982 |
JPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
604231 |
Oct 1990 |
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