THE IMPACT OF CLEAN MOLTEN METAL PROCESSING ON TOTAL OPERATIONAL COST IN THE PRODUCTION OF FERROUS ALLOY INVESTMENT CASTINGS

摘要

This paper concerns the application of Air Liquide Industrial U.S. LP's patented SPAL™ process to the induction furnace heats of ferrous alloys at Spokane Industries Precision Castings Division in Spokane, Washington. The tests were conducted in order to explore the range of possible operational cost and cast condition changes that occur when a clean molten metal matrix is produced during an induction furnace melt cycle protected by an inert argon blanket on the melt interface. Parameters such as furnace lining life, pouring temperature, fluidity, de-oxidation practice, charge mix, tensile strength, rework, and scrap are reviewed in reference to the ferrous alloy systems tested in this paper. The results included a significant increase in lining life, a reduction in pouring temperature, an increase in molten metal fluidity, a complete elimination of the foundry de-oxidation practice in the melt furnace, a significant decrease in the cost of the charge mix per heat, an increase in tensile strength, a decrease in rework, and a decrease in scrap. Details of these results are presented. The test procedures are also reviewed, as well as the overall foundry impact of production application of the SPAL™ process at Spokane Industries.