Production of thin, oriented siliconiron wherein grain growth inhibitor is added to primary recrystallization heat treatment atmosphere as function of mn content and final thickness

Claim 1

IN A PROCESS OF PRODUCING CUBE-ON-EDGE ORIENTED SILICON-IRON STOCK CONTAINING FROM ABOUT 2% TO ABOUT 3.5% SILICON AND COMPRISING THE STEPS OF HOT REDUCING THE SILICON-IRON, REMOVING THE SCALE, COLD ROLLING TO FINAL GAUGE, AND SUBJECTING SAID STOCK TO A FINAL ANNEAL CONSISTING OF A PRIMARY GRAIN GROWTH STAGE AND A SECONDARY GRAIN GROWTH STAGE; THE IMPROVEMENT COMPRISING THE STEPS OF PROVIDING SAID SHEET STOCK WITH AN INITIAL MANGANESE CONTENT FROM ABOUT .03% TO ABOUT .15%, COLD ROLLING SAID STOCK TO A FINAL THICKNESS OF ABOUT 7 MILS AND LESS, PROVIDING A GRAIN GROWTH INHIBITOR IN THE ENVIRONMENT OF THE STOCK DURING SAID PRIMARY GRAIN GROWTH STAGE AND DIFFUSING SAID INHIBITOR INTO THE GRAIN BOUNDARIES OF SAID STOCK DURING SAID PRIMARY GRAIN GROWTH STAGE, WHEREBY TO FAVOR THE GROWTH OF CUBE-ON-EDGE ORIENTED NUCLEI DURING SAID SECONDARY GRAIN GROWTH STAGE, SAID INHIBITOR BEING CHOSEN FROM THE CLASS CONSISTING OF SULFUR, SELENIUM AND COMPOUNDS THEREOF, AND ADJUSTING THE QUANTITY OF SAID INIBITOR IN PROPORTION TO THE SAID MANGANESE CONTENT AND THE FINAL THICKNESS OF SAID STOCK.