奥贝体钢轨和珠光体钢轨气压焊接头界面行为及力学性能分析  

Interface Behavior and Mechanical Properties of the Gas Pressure Welding Joints of Bainite Rail and Pearlite Rail

作　　者：谢航 戴虹[1] 唐充 XIE Hang;DAI Hong;TANG Chong(School of Material Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学材料科学与工程学院,四川成都610031

出　　处：《电焊机》2022年第11期22-30,共9页Electric Welding Machine

基　　金：国家重点专项研发项目(2017YFB4501)。

摘　　要：采用气压焊对U26Mn奥贝体钢轨和U75V珠光体钢轨混焊进行研究,通过OM、SEM、冲击、拉伸、硬度试验探究异种钢轨气压焊接头焊缝界面的冶金结合特征与力学性能水平。结果表明:气压焊接头焊缝界面两侧存在元素扩散行为,焊缝界面金属在热机循环作用下发生了交互结晶和再结晶,冶金结合良好(除轨底脚外);焊态接头平均强度达到贝氏体钢轨母材的86%,正火态接头平均强度达到贝氏体钢轨母材的90%;焊态接头轨顶面平均硬度、软化区平均硬度及宽度均满足TB/T1632《钢轨焊接》标准要求;接头中存在硫化物夹杂,对接头冲击韧性有较大影响。The mixed welding of U26Mn A-B rails and U75V pearlite rails is studied by gas pressure welding methods,and the metallurgical bonding characteristics and mechanical properties of the weld interface of the gas pressure welding joints of dissimilar rails are explored through OM, SEM, impact, tensile, and hardness tests. The results show that there is element diffusion behavior on both sides of the weld interface of the gas pressure welded joint.The metal at the weld interface has undergone mutual crystallization and recrystallization under the action of heat-mechanical cycles,and the metallurgical combination is good(except rail feet). The average strength of welded joints reaches 86% of the base material of bainite rail, and the average strength of normalized joints reaches 90% of the base material of bainite rail. The average hardness of the rail top surface and the softened zone, as well as the width of the softened zone of the welded joint meet the standard requirements of TB/T1632 "Rail Welding". The presence of sulfide in the joint has a great influence on the impact toughness of the joint.

关 键 词：贝氏体+珠光体 钢轨 气压焊 元素扩散 力学性能 

分 类 号：TG453.2[金属学及工艺—焊接]