Research Of Microstructure Change And Texture Variation Of Hi-B Steel With An Element Of Cu Produced By Stimulated CSP Process

The energy-saving and environment-friendly CSP process has been the hot topic among steel factories and related research institutions under the background of available energy becoming less and intense competition in the silicon steel market.The CSP process has a property of low temperature heating.The Cu2 S inhibitor can match the property well because its solution temperature is lower than that of traditional inhibitor AlN and MnS in the process of silicon steel production.The test Hi-B steel with an element of Cu produced by stimulated CSP process is investigated with the guidance of industrial producing experience.The microstructure change and the texture variation in hot rolling,normalizing,cold rolling and primary recrystallization annealing process are respectively studied with Zeiss Axioplan optical microscope and NOVA400 Nano SEM.The experiment results show that there exist microstructure gradients from the surface to the center of the plant in hot rolling period,which can be described as recrystallized zone,mix-grain zone and deformed zone.The hot rolling sample cooling to 580℃ with water and then cooling to room temperature with air（air cooling sample）has a little bigger grain size than the sample cooling to room temperature with water（water cooling sample）in the surface zone.The air cooling sample has a bigger percent of Goss texture and a smaller percent of {110}<112> texture than that of water cooling sample besides a more sharper Goss texture.The normalizing process has the function of making the microstructure gradient more obvious and decreasing the zonal structure of the center of the plant investigated.Different annealing processes are applied to samples with different reduction ratio of cold rolling,under which a conclusion is reached that the proper annealing process is 850 ℃ ×5min and the suitable reduction ratio is 88% when some factors like the percent of textures,CSL grain boundary andα,γ,ε alignment line are taken into consideration.When the sample taking Cu₂S+AlN as main inhibitor and the sample taking AlN+MnS as main inhibitor are contrasted,it turns out that the former has a better inhibition effect after the analysis of grain size,texturecontent and CSL grain boundary.