Effect of Cold Reduction Ratio on Microstructure Textures and Mechanical Property of IF Steel

Hot rolled IF steel was used to study the effect of cold reduction ratio on the microstructure textures and mechanical properties of Ti-IF and Ti+Nb-IF steel after batch annealing processes.The results showed that recrystallization of the IF steels was rudimentarily finished after batch annealing,the grain shape is pancake;and the grain size diminishes as the cold reduction ratio was increased;the strain hardening exponent n value was gradually reduced.The plastic strain ratio value(r_90°) of Ti+Nb-IF steel reached the maximum with the higher carbon content and cold reduction ratio of 70%,or with the lower carbon content and cold reduction ratio of 80%;the plastic strain ratio value(r_90°) of Ti-IF steel reached the maximum with cold reduction ratio of 70%;however,when the cold reduction ratio was increased,the textures of IF steel was stronger,then the {223}<110>、{114}<110>and {111} textures of lower cold reduction ratio were changed to {223}<110>、{111}<110>and {114}<110> textures of higher cold reduction ratio,and the textures trend toward {111} texture.