High-temperature alloy
View Patent ↗An iron-based high-temperature alloy has the following chemical composition (values given being in % by weight): 20 Cr, 4 to 8 Al, at least one of the elements Ta and Mo with a sum of 4 to 8, 0-0.2 Zr, 0.02-0.05 B, 0.1-0.2 Y, 0-0.5 Si, remainder Fe. The alloy can be produced at low cost and is distinguished in comparison with the known prior art by outstanding oxidation resistance and good mechanical properties at high temperatures up to 1000° C.
1. An iron-based high-temperature alloy, comprising the following chemical composition, with values in % by weight:
20 Cr,
4 to 8 Al,
at least one of Ta and Mo, wherein the sum (Ta+Mo)=4 to 8,
0-0.2 Zr,
0.02-0.05 B,
0.1-0.2 Y,
0.25-0.5 Si,
remainder Fe.
2. The high-temperature alloy as claimed in claim 1 , comprising 5 to 6% by weight Al.
3. The high-temperature alloy as claimed in claim 2 , comprising 5.5 to 6% by weight Al.
4. The high-temperature alloy as claimed in claim 1 , comprising 0 to 8% by weight Mo and/or 0 to 4% by weight Ta, wherein the sum (Mo+Ta) is in the range from 4 to 8% by weight.
5. The high-temperature alloy as claimed in claim 4 , comprising 2% by weight Mo and 2% by weight Ta.
6. The high-temperature alloy as claimed in claim 4 , comprising 4% by weight Mo and/or 4% by weight Ta.
7. The high-temperature alloy as claimed in claim 1 , comprising 0.25% by weight Si.
8. The high-temperature alloy as claimed in claim 1 , comprising 0.5% by weight Si.
9. The high-temperature alloy as claimed in claim 1 , comprising 0.2% by weight Zr.
10. The high-temperature alloy as claimed in claim 1 , comprising 0.05% by weight B.
11. The high-temperature alloy as claimed in claim 1 , comprising 0.1% by weight Y.
12. A method for producing a high-temperature alloy, the method comprising:
providing the following elements, with values in % by weight,
20 Cr,
4 to 8 Al,
at least one of Ta and Mo, wherein the sum (Ta+Mo)=4 to 8,
0-0.2 Zr,
0.02-0.05 B,
0.1-0.2 Y,
0.25-0.5 Si,
remainder Fe;
melting said elements by an arc to form an alloy; and
after said melting, rolling said alloy at about 800-900° C.
13. A method of protecting a thermocouple, the method comprising:
providing an alloy as claimed in claim 1 ;
forming a tube from said alloy; and
positioning said thermocouple in said tube.