热输入对苛刻环境铁路货车用钢粗晶区组织与性能的影响

热输入对苛刻环境铁路货车用钢粗晶区组织与性能的影响 Effects of welding heat input on the microstructure and performance of coarse grained region of steel for railway freight cars in harsh environment 马清波 MA Qingbo 1 first-author 黄显锋 HUANG Xianfeng 1 韩景茹 HAN Jingru 1 黄君辉 HUANG Junhui 1 李程 LI Cheng 2 corresp 773255855@qq.com 中车齐齐哈尔车辆有限公司 中车齐齐哈尔车辆有限公司 CRRC qiqihar vehicle Co.,Ltd. CRRC qiqihar vehicle Co.,Ltd. 大连交通大学 大连交通大学 School of Materials Science and Engineering,Dalian Jiaotong University School of Materials Science and Engineering,Dalian Jiaotong University 采用焊接热模拟技术,模拟焊条电弧焊不同热输入对苛刻环境铁路货车用钢粗晶区组织和性能的影响。试验结果表明:不同热输入粗晶区的热模拟组织为先共析铁素体沿晶界向晶内生长,晶内有粒状贝氏体、针状铁素体和少量板条马氏体,热输入越小,板条马氏体越多,晶粒越细;硬度随着热输入增加而减小,不同热输入粗晶区热模拟试件均具有良好的冲击性能,尤其是低温冲击性能优异,细晶强化是苛刻环境铁路货车用钢不仅具有较高的强度,也具有良好韧性的主要原因。 Welding heat simulation technology is used to simulate the effects of different heat inputs of manual arc welding on the microstructure and performance of the coarse grain region of steel for railway freight cars in harsh environments. The test results show that the microstructures of coarse grained regions with different heat inputs are proeutectoid ferrite growing into the crystal along the g rain boundary,there are granular bainite,acicular ferrite and a little lath martensite in the crystal. The lower heat input,the more lath martensite and the finer the grain. The hardness of the test piece reduces as the heat input increases. All coarse grained regions of the thermal simulation test pieces with different welding heat inputs have good impact performance,especially the low temperature impact performance is excellent. Fine grain strengthening is a main reason that steel for railway freight cars in harsh environment has high strength and good toughness. 苛刻环境铁路货车用钢 焊条电弧焊 热模拟 组织性能 steel for railway wagons in harsh environments manual arc welding thermal simulation organizational performance U270.41;TG444;TG142.1 国家重点研发计划课题资助项目（2017YFB0304605） 2022-03-08 12 50