Non-textured electrical steel sheet, useful for cores in rotary electrical machines such as motors and generators, is produced by multi-pass hot rolling mainly in the two-phase austenite-ferrite region

摘要

Non-textured electrical steel sheet production, by multi-pass hot rolling mainly in the two-phase austenite/ferrite region, is new. Production of non-textured electrical steel sheet, from a starting material, such as cast slabs, strips, plates or thin slabs, of a steel of composition (by wt.) 0.001-0.05% C, = 1.5% Si, = 0.4% Al, = 1.7% Si + 2Al, 0.1-1.2% Mn, balance Fe and impurities and Ni, Co, Nb and/or B additions, comprises subjecting the starting material, directly after casting or after reheating to 1000-1180 deg C, to multi-pass hot rolling to strip and then coiling, whereby during the hot rolling at least the first pass is performed in the austenite region, at least one further pass being carried out in the two-phase austenite/ferrite region with a total deformation ( iota h) of -35%.