焊接电流作用下高性能桥梁钢接头性能的演化  

Evolution of Performance of High Performance Bridge Steel Joints on Welding Current

作　　者：郝玉朋 HAO Yupeng(Metals and Chemistry Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)

机构地区：[1]中国铁道科学研究院集团有限公司金属及化学研究所,北京100081

出　　处：《高速铁路新材料》2023年第4期25-29,共5页Advanced Materials of High Speed Railway

基　　金：中国铁道科学研究院集团有限公司金属及化学研究所科研基金项目(2021SJ01)。

摘　　要：埋弧焊过程中焊接电流对焊丝的熔化速度和母材的熔化深度至关重要,也在很大程度上影响焊接接头的性能。研究了热输入恒定的条件下,500 MPa级耐候桥梁钢接头性能的演化规律。利用金相分析、准静态拉伸、示波冲击等材料组织和性能测试手段,重点研究了焊接电流对接头力学性能,尤其是冲击性能的影响。结果表明:热输入控制在25 kJ/cm时,在540~630 A的范围内调节焊接电流,不会明显改变熔敷金属和接头的抗拉强度;电流对冲击吸收能量的影响不明显;焊缝裂纹萌生功基本保持恒定,裂纹扩展功是导致焊缝冲击吸收能量增加的主要因素。焊接电流控制在600 A左右时,焊缝冲击吸收能量较高,同时,裂纹扩展功处于较高水平。In the process of submerged arc welding,welding current is very important to the melting speed of welding wire and the melting depth of base metal,and also affects the performance of welded joints to a large extent.The evolution of the performance of 500 MPa grade weather resistant bridge steel joints under constant heat input conditions was investigated in this article.The influence of welding current on the mechanical properties of joints,especially impact properties,was mainly studied using metallographic analysis,quasi-static tensile testing,oscillographic impact testing and other material organization and performance testing methods.The results show that when the heat input is controlled at 25 kJ/cm,adjusting the welding current within the range of 540~630 A will not significantly change the tensile strength of the deposited metal and joint.The effect of current on shock absorption energy is not significant.The initiation work of weld crack remains basically constant,and the crack propagation work is the main factor leading to an increase in energy absorption by weld impact.When the welding current is controlled at around 600 A,the impact absorption energy of the weld seam is higher,and at the same time,the crack propagation work is at a higher level.

关 键 词：高性能桥梁钢 埋弧焊 焊接电流 示波冲击 接头性能 

分 类 号：TG444[金属学及工艺—焊接]