Research Of Inhibitor Precipitation Of Hi-B Steel With An Element Of Cu Produced By Stimulated CSP Process

Studies have shown that,comparing with the traditional steel manufacturing,the advanced and short process which based on the CSP the thin slab continuous casting and rolling has significant characteristics such as high quality and low cost in the production field of electrical silicon steel.Thus,it has become one of popular topics.This topic trial-produce Hi-B steel containing Cu 0.4%through the simulation of CSP technology,then observe micro-structure and inhibitor in various processes respectively,thus study the change of micro-structure and inhibitors.The results show that,the precipitation inhibitors after hot rolling are mainly Cu₂S,the center layer is more and the average size is small,as the surface layer is relatively less,but the average size relatively larger.Samples after hot rolling from880℃water cooling to 580℃and then cooled to room temperature in air precipitate inhibitor are more,but the average size are smaller relatively.After normalizing,inhibitors precipitate further,which most are Cu2S,also a small amount of AlN.With the condition 850℃×5min of primary recrystallization annealing,the sample precipitation inhibitors are relatively more,which micro-structure conform to requirements of average grain size for the high temperature annealing.After nitriding annealing at low temperature（550℃,600℃,650℃）,the precipitation inhibitors are mainly（Si,Mn）N and a little AlN,and with the increase of temperature,precipitation increase.After 900℃high temperature nitriding annealing,the precipitation inhibitors are mainly AlN.The initial temperature of abnormal growth is about between 1030℃and 1040℃in the secondary recrystallization.Before abnormal growth,the precipitation inhibitors are mainly dispersed,and the average grain size is relatively small;When it begin to abnormal growth,inhibitors are begining to gathered,coarsening and even dissolve,the number reduced and the average grain size increased.