Claims
- 1. A method of reducing the carbon content of an alloy based on a metal selected from the group consisting of iron, cobalt and nickel and also containing carbon and at least 10% by weight chromium by introducing into the molten alloy, through at least one inner section of a tuyere which comprises at least two concentric tubes, a first gas which is essentially pure steam or a mixture of steam and an inert gas selected from the group consisting of nitrogen, argon, helium, neon and xenon, said first gas bringing about an endothermic reaction when it meets the molten alloy, and introducing through an outermost section of the tuyere a second gas which is a mixture of gaseous oxygen and a gas selected from the group consisting of steam, nitrogen, argon, helium, neon and xenon, the gaseous oxygen content in said second gas being between 5 and 30% by volume, said second gas undergoing an exothermic reaction when it meets the molten alloy, said second gas being introduced into the molten alloy at the same time as said first gas is introduced to prevent blockage of the tuyere by frozen steel.
- 2. A method according to claim 1 wherein the flow of second gas through the outermost section of the tuyere represents 10 to 20% by volume of the total gas flow through the tuyere.
- 3. A method according to claim 1 wherein said second gas contains 10 to 30% by volume of oxygen.
Priority Claims (2)
Number |
Date |
Country |
Kind |
7400831 |
Jan 1974 |
SW |
|
12907/72 |
Oct 1972 |
SW |
|
Parent Case Info
This application is a continuation-in-part of our co-pending application Ser. No. 403,854 filed Oct. 5, 1973, now U.S. Pat. No. 3,867,136.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
1,450,718 |
Jul 1966 |
FR |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
403854 |
Oct 1973 |
|