GB1062744A - Production of cube-on-edge oriented silicon-iron - Google Patents

Abstract

Silicon-iron sheet having (110) [001] orientation is made by casting silicon-iron containing at least 1.8% Si and preferably at most 3.5% into a casting 0.1 to 0.5 inch thick, e.g. by vacuum drawing the melt into a thin mould, allowing the casting to cool preferably at a rate sufficient to retain MnS in solution or as finely dispersed precipitate, subjecting the casting to a double cold roll with 40-80% reduction, each roll being followed by an intermediate anneal at 1300-1800 DEG F., then a final cold roll with 40-70% reduction and a final anneal at above 1800 DEG F. e.g. above 2200 DEG F. The casting may be annealed prior to the first cold roll. A decarburization just prior to the final anneal is preferred. The intermediate anneals may be carried out using a neutral or reducing atmosphere, e.g. cracked ammonia, partially combusted gases or hydrogen. The silicon-iron alloy, which may be refined in an open-hearth furnace and melted in an electric furnace, preferably comprises 2.9 to 3.3% Si, 0.01 to 0.04% C, 0.06 to 0.12% Mn, 0.015 to 0.04% S, and balance Fe.