基于高温回火的高强钢焊丝带状组织调控  

Control of banded structure in high strength welding wire based on high temperature tempering

作　　者：张敏敏[1,2] 朱腾辉 李达 罗涛[3] 任希乐 ZHANG Minmin;ZHU Tenghui;LI Da;LUO Tao;REN Xile(School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China;Zibo Railway Section,China Railway Ji'nan Bureau Group Co.Ltd.,Zibo 255000,China;Sichuan Xiye New Material CO.,Ltd.,Chengdu 611730,China)

机构地区：[1]西南交通大学材料学院,成都610031 [2]中国铁路济南局集团有限公司淄博工务段,淄博255000 [3]四川西冶新材料有限公司,成都611730

出　　处：《焊接学报》2018年第2期124-128,134,共6页Transactions of The China Welding Institution

摘　　要：对800 MPa级高强钢气保焊丝进行630~700℃热处理,研究了不同高温回火温度对高强钢焊丝带状组织、强度、塑性及冲击韧性的影响.结果表明,回火后焊丝主要由类回火索氏体基体及随机分布的粒状贝氏体组成,随着回火温度的升高,粒状贝氏体减少,而类回火索氏体的组织增多,焊丝经轧制后形成的粒状贝氏体型带状组织得到显著改善.焊丝的强度随回火温度的升高呈不断上升的趋势,但都低于原始态.当回火温度为700℃时抗拉强度为836 MPa,冲击吸收功可达148 J,较未回火前提高近5倍,断后伸长率可达26.5%,为回火前的6倍,回火后焊丝冲击韧性和塑性得到显著改善.The 800 MPa grade high strength welding wire for gas shield metal arc welding was tempered at the temperature range from 630℃to 700℃and the isothermal time of 12 hours,and the banded structure evolution,strength,plastic and impact toughness of the tempered wire were investigated.The results reveal that the microstructures of welding wire at different tempering temperature are mainly composed of similar tempered sorbite substrate and random distribution of granular bainite.The amount of the granular bainite decrease while the one of similar tempered sorbite increases with the increase of tempering temperature.The granular bainite banded structure in welding wire occurred after rolling can be evidently controlled.The yield strength of the welding wire increases with the increase of tempering temperature,but it is lower than the original value.The value of the yield strength of welding wire tempered at 700℃is 836 MPa,meanwhile,the impact toughness and elongation can reach up to 148 J and 26.5%,respectively,which is 5 times and 6 times higher than that without tempering.The plasticity and impact toughness are significantly improved after tempering.

关 键 词：高温回火 高强钢气保焊丝 带状组织 力学性能 

分 类 号：TG424[金属学及工艺—焊接]