METHOD FOR STABLE MANUFACTURING GRAIN-ORIENTED ELECTRICAL STEEL SHEETS AND A SLAB USING THEREFOR

摘要

PURPOSE: A grain oriented electrical steel sheet slab and a manufacturing method thereof are provided to safely manufacture a grain oriented electrical steel sheet using middle temperature heating process. CONSTITUTION: A grain oriented electrical steel sheet slab comprises Si 2.0~5.0 weight%, acid soluble Al 0.01~0.04 weight%, less than Mn 0.20 weight%, less than N and S 0.003~ 0.006 weight%, Bi 0.01~0.05 weight%, and the rest Fe and other inevitable impurities. N and S is an inhibitor forming element. Bi is a critical segregation element. Slab is re-heated to the middle temperature range of 1200~1300°C. A first re-grain size is 8~20μm in an annealing process.