Combined Al-Si-Ca Treatment of EAF-VD Steel to Develop Replacements for Some ESR Steels with Comparable Quality, Lower Manufacturing Cost, and Environmental Impact

摘要

This research sets out to study the possibility of applying combined aluminum-silicon-calcium treatment of molten steel in conventionally manufactured electric arc furnace vacuum degassed steel grades. The studied melts were intentionally engineered to have the lowest possible amount of defects that were designed to be the least detrimental to the final product properties and then cast into ingots with optimized size and shape to reach a very high cleanliness, low segregation, and high material isotropy in products that were forged with a total reduction ratio of less than ten. A set of extra quality assurance operations was also added to the production process of these products to ensure their final superior quality. To evaluate the final outcomes of these operations, several through-hardening steels and carburizing steels used in bearing manufacturing and tool steel grades used in hot and cold tool/die manufacturing that were treated accordingly were chosen and analyzed for their micro/macro cleanliness, elemental segregation, and impact toughness at different sampling directions. These results were compared to those achieved from analyzing some electro-slag remelted (ESR) steels according to the same testing procedure. The final evaluations revealed that it is possible to manufacture a number of steel grades by means of an electric arc furnace-vacuum degasser process that fulfill the quality requirements that are traditionally known to be specific for some ESR steels. These findings could lead to some steel grades that are manufactured with less total cost of manufacturing, less negative impact on the environment, and a higher sourcing possibility compared with similar ESR grades.