Inclusion removal from Cr-Ni steel and Ni-base alloys using ceramic foam filters

摘要

Filtration tests on Al-killed (r-Ni steels (17.5 percent Cr,115 percent Ml) and Ni-based alloys (20 percent Cr,10 percent Mo, 03 percent Al) were made in a 50 kg vacuum induction melting and casting unit using commercial ceramic foam filters. Al_2O_3 inclusions were produced by addition of Alto the oxidized metal. The ingot weight was in the order of 25 kg. Filtration efficiencies, based on chemically analysed total oxygen content or particle size distribution as determined by quantitative metallography, were evaluated. Furthermore, attempts were made to determine filter resistance and volume flow capacities of various filters.