冶金锯片用65Mn钢轧制工艺参数的热模拟优化

摘要

In order to develop a narrow range of parameters of controlled rolling and controlled cooling process in laboratory,the influences start rolling temperature,finish rolling temperature,coiling temperature, cooling rate from finish pass to coiling and cooling rate after coiling on microstructure and hardness of 65Mn steel were studied by thermal simulation tester.The results show that the most influential parameters for hardness of 65Mn steel was cooling rate after coiling.The higher start rolling temperature,finish rolling temperature and coiling temperature were beneficial for the growth of original austenite grain and recrystallization grain,and then the grains size after rolling was bigger,this lead to the decrease of hardness and strength.Under the same rolling parameters, with the decrease of cooling rate after coiling,the average grain size increased obviously and the content of proeutectoid ferrite increased in some degree.The best controlled rolling and controlled cooling parameters were start rolling temperature of 1 170 ℃,fininsh temperature of 890 ℃,coiling temperature of 680 ℃,cooling rate from finish rolling to coiling of 10 ℃.s-1 ,cooling rate after coiling of 0.05 ℃.s-1;under the parameters,the hardness of the tested steel was 19.9 HRC.%为制定65 Mn钢窄范围实验室控轧控冷工艺参数,采用热模拟试验机研究了开轧温度、终轧温度、卷取温度、终轧至卷取冷速以及卷取后冷速对其显微组织与硬度的影响.结果表明：影响65 Mn 钢硬度最显著的工艺参数为卷取后冷速；较高的开轧温度、终轧温度和卷取温度使得65 Mn钢原始奥氏体晶粒和再结晶晶粒长大,从而使轧制变形后的晶粒尺寸也较大,进而降低了最终产品的硬度和强度；在相同的工艺参数下,随着卷取后冷速降低,65 Mn 钢的平均晶粒尺寸明显变大,先共析铁素体含量有所增加；最佳的控轧控冷工艺参数为开轧温度1170℃,终轧温度890℃,卷取温度680℃,终轧至卷取冷速10℃.s－1,卷取后冷速0．05℃.s－1；在此工艺下试验钢的硬度为19．9 HRC.