Effects of Homogenization Conditions and Hot Rolling Parameters on Grain Refinement of an As-Cast 301 Stainless Steel

 In this work, effects of homogenization time of 3 to 13 h at 1200 °C on the grain refinement of as-cast AISI 301 stainless steel after different hot rolling conditions were investigated. The results showed that the minimum grain size of 16±7 mm was achieved when homogenization took place at 1200 °C for 9 h followed by hot rolling at temperature range of 1000–1200 °C with strain of 0.8 and strain rate of 1.2 s-1 and annealing at 1050 °C for 3 min. Effect of Nb element on the retardation of recrystallization was pronounced. It seems that there is an optimum solute segregation below which retardation and above which grain growth of recrystallized grains is dominant. It was also found that this optimum homogenization condition was dependent upon the hot rolling parameters; higher the strain and strain rate resulted in lower homogenizing time at 1200 °C.