耐候钢Q420qNH焊接粗晶区冲击韧性及耐电化学腐蚀性能  

Impact toughness and electrochemical corrosion resistance of simulated coarse-grained HAZ of weathering steel Q420qNH

作　　者：张侠洲 陈延清 王凤会 张熹 赵英建 ZHANG Xiazhou;CHEN Yanqing;WANG Fenghui;ZHANG Xi;ZHAO Yingjian(Research Institute of Technology of Shougang Group Co.,Ltd.,Beijing 100043,China;Beijing EngineeringResearch Center of Energy Steel Beijing 100043 China)

机构地区：[1]首钢集团有限公司技术研究院,北京100043 [2]北京市能源用钢工程技术研究中心,北京100043

出　　处：《电焊机》2018年第10期48-53,共6页Electric Welding Machine

摘　　要：使用热模拟试验机模拟耐候桥梁钢Q420qNH在不同焊接热输入下热影响粗晶区的热循环过程,研究粗晶区低温冲击韧性和耐电化学腐蚀性能。结果表明,随着热输入的增加,焊接热影响粗晶区组织由板条状贝氏体逐渐向粒状贝氏体过渡,t_(8/5)为30 s时,组织完全为粒状贝氏体,晶粒尺寸逐渐粗化,大角度晶界密度降低,止裂性能降低,吸收冲击功降低。此外,随着热输入的增加,腐蚀电流密度逐渐上升,交流阻抗值逐渐下降,焊接热模拟粗晶区的耐蚀性下降。最终确定耐候桥梁钢Q420qNH热输入不宜超过36 kJ/cm。Impact toughness and electrochemical corrosion resistance of simulated coarse-grained HAZ of weathering steel Q420qNHare studied in the paper. The coarse-grained HAZ is simulated by Gleeble2000D thermal simulation tester upon different heat inputenergy. The results show that the impact energy decreases with the increase of heat input energy, because the microstructure changesgradually into granular bainite （GB）from lathlike bainite （LB）, and the high-angle grain boundary density of coarse-grained HAZreduces gradually. In addition, the electrochemical corrosion resistance of coarse-grained HAZ is influenced by the heat input energy.As the heat input energy increases, the corrosion current density gradually increases and the AC impedance value gradually decreases.It is determined that the heat input energy should not exceed 36 kJ/cm for the weathering steel Q420qNH.

关 键 词：耐候桥梁钢 焊接热模拟粗晶区 冲击韧性 电化学腐蚀 

分 类 号：TG457.11[金属学及工艺—焊接]