Non-oriented silicon steel sheet with low watts loss - has boron and rare earth addns. and low carbon and aluminium contents

摘要

Sheet having uniform magnetic properties is made of a silicon steel of compsn. max. 0.015 (pref. max. 0.010)%C, 1.5-3.5% Si, 0.05-1.0% Mn, 0.005-0.08% acid soluble Al, max. 0.015% S, max. 0.010% O, max. 0.005% N, B in amt. to give a B:N ratio of 0.4-2.0, 0.001-0.020% rare earth element(s), balance Fe and impurities. Addn. of B to give the above B:N ratio results in a low Watts loss and addn. of the rare earth element(s) eliminates variations in magnetic properties.