摘要
文中对铌/钢进行了激光焊接,当激光束直接作用于铌/钢接触面时,由于Nb-Fe金属间化合物Fe_2Nb的生成呈现连续分布的特点会使焊后接头发生断裂.针对该问题,采用激光偏束焊对铌/钢进行焊接,通过激光束偏钢侧来抑制铌的熔化量,进而减少接头中Fe_2Nb的生成.结果表明,通过采用激光偏束焊的方式可以较好地抑制接头开裂的问题.组织分析表明,焊后接头组织主要由γ奥氏体相与一定量的Fe2Nb相及少量的δ铁素体组成.力学性能结果显示,断裂发生在接头Fe_2Nb金属间化合物层处,其抗拉强度为221 MPa,最高硬度出现在Fe2Nb金属间化合物层约为1 143 HV.
In this work,the Nb/304 SS joint was welded by laser welding.The joint fractured immediately due to continuously distributed Fe_2Nb intermetallic compounds when the laser was directed to the Nb/steel interface.In order to solve the problem,the laser beam-offset welding procedure was proposed.The amount of melted niobium was reduced by the laser offset effect.Finally,the formation of Fe_2Nb intermetallic compounds was controlled.The results showed that laser beam-offset welding was an ideal way to control the joint crack which occurred in laser centered welding condition.The joint microstructure was mainly consisted of γ austenite phase and a certain amount of Fe_2Nb intermetallic compounds with little δ ferrite phase.The tensile strength of the joint was 221 MPa,the fracture occurred in the Fe_2Nb intermetallic compounds layer.The highest microhardness existed in Fe_2Nb intermetallic compounds layer with a value of 1 143 HV.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2017年第3期41-44,共4页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51605205)
江苏省高校自然科学研究面上项目(15KJB460009)
关键词
铌
304不锈钢
激光焊接
金属间化合物
显微组织
niobium
304 stainless steel
laser welding
intermetallic compound
microstructure
