Gussteilen aus Superlegierung mit extrem niedrigem Schwefelgehalt und Verfahren zur Herstellung

摘要

Directionally solidified superalloy components having a bulk sulfur concentration of less than 1 part per million by weight are provided by vacuum melting a charge to form a superalloy melt, desulfurizing the melt by contact with a calcium-bearing desulfurizing agent for a time to reduce sulfur concentration of the melt to less than 1 ppm by weight, casting the melt directly or following solidification and remelting in a ceramic investment mold, and directionally solidifying the melt as cast components without adverse bulk sulfur pick-up subsequent to desulfurization to provide castings having a sulfur content below 1 ppm, such as in the range of hundreds of parts per billion to provide significantly improved oxidation resistance.