软铁弹带TIG堆焊工艺及组织性能研究  

Investigation on structure and mechanical properties of pure iron bearing band for tungsten inert-gas cladding

作　　者：吕世雄[1] 黄永宪[1] 磨安祥[1] 敬小军[1] 徐永强[1] 

机构地区：[1]哈尔滨工业大学先进焊接与连接国家重点实验室,150001

出　　处：《焊接》2012年第2期41-45,55,共6页Welding & Joining

基　　金：国家自然科学基金(50974046;50904020);哈尔滨市青年科技创新人才基金(2009RFQXG050);中央高校基础科研业务费专项资金(HIT.NSRIF.2012007);国家博士后科学基金(20090460883;201003419)

摘　　要：针对炮弹钢基体表面堆敷铜合金时存在泛铁问题等不足,创新性地提出用软铁代替铜合金作为堆焊金属,开展了纯铁弹带TIG堆焊工艺的研究。主要针对软铁弹带的力学性能和软铁堆焊的界面组织特征进行了深入研究。研究表明:与铜/钢堆焊形成的铜弹带比较,软铁弹带的硬度值大约为170 HV,剪切强度约为280 MPa,与铜弹带的力学性能相差不大。软铁堆焊界面上靠近熔合线的热影响区为马氏体组织,熔合线不明显,有基体合金熔化进入堆焊层,堆焊层为先共析铁素体和贝氏体类型组织,同时发现基体中的碳等合金元素也进入界面层。采用软铁作为堆焊金属可降低堆焊弹带的热裂纹倾向,避免了堆焊过程中因铜渗入钢基体而导致的晶间渗透裂纹。经过堆焊工艺优化实现了界面层组织结构的优化,最终获得了理想的纯铁弹带。In order to solve the problem of iron return when the copper alloy was coated on steel substrate,the pure iron welding was selected to replace copper metal,and tungsten inert gas(TIG) cladding method was adopted.The effect of processing condition on mechanical properties of the pure iron bearing band and the interface behavior of pure iron/steel was studied.The results show that,the mechanical performance of pure iron bearing band is close to that of copper one with a 170 HV in hardness and 280 MPa in shear strength.The microstructure analyzed result indicated the martensite formed at the heat affected zone near the fusion line,and the fusion zone is not undistinguished.Part of substrate melted and was transferred to the coated layer,where the phase structure includes proeutectic ferrite and bainite-type structure.The pure iron can reduce the hot cracking in the rotating band and avoid the infiltrated cracks caused by the mixture of copper element and steel during the cladding process.After the optimization of processing parameters,the growth of interfacial structure was controlled and the ideal cladding process of pure iron band was obtained.

关 键 词：软铁 TIG堆焊 界面组织 

分 类 号：TG44[金属学及工艺—焊接]