MANUFACTURE OF MOLTEN STEEL FOR NONORIENTED ELECTRICAL STEEL SHEET HAVING SMALL IRON LOSS

摘要

PURPOSE:To manufacture a molten steel for a nonoriented electrical steel sheet having a small iron loss and superior magnetic characteristics by refining a molten silicon steel contg. specified amounts of Si and Mn in a converter and by deoxidizing it with Si and an REM alloy in two steps to reduce the Al and O contents. CONSTITUTION:A molten silicon steel contg. 0.1-<1.0wt% Si and 0.1-1.0wt% Mn is refined in a converter and sent to a vacuum degassing stage, where it is deoxidized with Si and an REM alloy in two steps to reduce the amounts of acid-sol. Al and O contained in the steel to <=0.001wt% acid sol. Al and <=0.0050wt% O. A molten steel for a nonoriented electrical steel sheet having a small iron loss is manufactured.