亚共析钢片状渗碳体球化行为及轧制变形量的影响

Spheroidization behavior of lamellar cementite in hypoeutectoid steel and effect of rolling deformation

结合实际生产S35C成分精冲钢,讨论了亚共析热轧钢板片状渗碳体的退火球化行为及转变机制,并采用Gleeble热模拟试验机研究了热轧和冷轧变形量对精冲钢片状渗碳体快速球化效果的影响。结果表明,与850℃30%应变量相比,60%大变形量可有效细化组织,促进层片状珠光体断裂,显著加快热轧板球化速率,提高粒状渗碳体的均匀分布。冷轧大变形也有利于片状渗碳体的快速球化退火,但50%过高应变量会导致钢板退火后难以消除加工硬化,S35C精冲钢冷轧合适的变形量约在40%。

Spheroidization behavior and transformation mechanism of lamellar cementite in hot-rolled S35 C hypoeutectoid fine blanking steel were discussed. The influenceof deformation reduction on spheroidizing behavior of lamellar cementite in S35 C steel during hot rolling and cold rolling process was studied by Gleeble thermal simulation tester. The results show that the large deformation during hot rolling can refine the microstructure,promote the broken of lamellar pearlite,improve the uniform distribution of the granular cementite and significantly accelerate the spheroidizing rate of lamellar cementite. The large cold deformation of 50% can improve spheroidizing rate of lamellar cementite,but its work hardening is not easy to eliminate by annealing. Thus,the appropriate deformation reduction for cold rolling of S35 C fine blanking steel is recommended to be about 40%.