PLASMA ARE REMELTING OF STEELS AND NICKEL-BASED SUPERALLOYS

The IRC Plasma Are Cold Hearth Remelting (PACHR) furnace has been used to produce 100mm and 150mm diameter ingots of alloy 718, M50 bearing steel and G110 maraging steel from VIM/VAR feedstocks. These trials highlighted the importance of accurately controlling the level of the melt pool surface in the crucible in order to produce an acceptable ingot finish. Chemical analysis of the ingots produced indicated no significant changes in the level of any element. Cleanness of the ingots has been assessed using the Electron Beam Button Melt (EBBM) technique. The results obtained are encouraging but highlight the necessity for careful control of the plasma remelting process.