焊接热输入对高性能桥梁钢接头组织和性能的影响  

Effect of Welding Heat Input on Microstructure and Properties of Welded Joints of High-performance Bridge Steel

作　　者：郝玉朋 李力 高振坤 丁韦 胡玉堂 宋栋良 HAO Yupeng;LI li;GAO Zhenkun;DING Wei;HU Yutang;SONG Dongliang(Metals and Chemistry Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;CRRC Construction Engineering Co.,Ltd.,Beijing 100078,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 [2]中车建设工程有限公司,北京100078

出　　处：《高速铁路新材料》2022年第6期16-21,共6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：高性能桥梁钢是建造高性能铁路桥梁的关键材料,焊接是实现高性能桥梁钢性能优势的关键工艺过程。影响接头质量的诸多因素中,焊接热输入不仅关系到焊接效率,而且影响接头组织和力学性能,是决定接头质量的关键参数。以500 MPa级耐候桥梁钢为对象,综合利用金相分析、准静态拉伸、示波冲击、显微硬度等材料组织和性能测试手段,重点研究了焊接热输入对接头微观组织及其演化规律的影响,分析了焊接热输入对接头力学性能的影响。结果表明:采用埋弧焊加工时,在30~80 kJ/cm范围内,提高焊接热输入将导致接头抗拉强度和屈服强度下降,大幅降低其冲击韧性,接头脆性明显增大。500 MPa强度等级桥梁钢焊接热输入宜控制在50 kJ/cm以下,优选为不超过30 kJ/cm,以保证接头具有良好的综合力学性能同时兼顾较高的生产效率。High-performance bridge steel is the key material for building high-performance railway bridges,and welding is the key process to realize the performance advantages of high-performance bridge steel.Among the many factors that affect the quality of the joints,the welding heat input is not only related to the welding efficiency,but also has a particularly significant impact on the formation of the weld microstructure and the mechanical properties of the joint,and is a key parameter that determines the quality of the joints.In this paper,500 MPa grade weathering bridge steel had been introduced,comprehensively using metallographic analysis,quasi-static tensile,instrumented impact,microhardness and other material microstructure and performance testing methods,the focus of the welding heat input on the microstructure and evolution of the weld was studied.The effect of welding heat input on the mechanical properties of the joint was investigated.The results show that in the range of 30~80 kJ/cm,increasing the welding heat input will lead to a decrease in the tensile strength and yield strength of the joint,a sharp decrease in the impact toughness,and a significant increase in the brittleness of the joint.When submerged arc welding is used,the welding heat input of bridge steel of this strength grade should be controlled below 50 kJ/cm,preferably not more than 30 kJ/cm,to ensure that the joint has good comprehensive mechanical properties and high production efficiency.

关 键 词：高性能桥梁钢 埋弧焊 焊接热输入 示波冲击 屈服强度 

分 类 号：TG444[金属学及工艺—焊接]