Cu基药芯焊丝TIG焊TA1/Q235B接头微观组织和显微硬度

Microstructures and microhardness of TA1/Q235B joints welded by TIG with Cu-based flux-cored wire

利用Cu基(Cu-Cr-Co-Ni)药芯焊丝对TA1/Q235B异种金属对接与搭接接头进行了TIG焊接试验.通过SEM、EDS和XRD对接头微观组织进行了详细分析,通过显微硬度测试了接头的硬度分布.结果表明,采用Cu基药芯焊丝进行TA1/Q235B TIG焊接,对接和搭接均得到了无缺陷的接头.两种接头的焊缝与母材界面处组织分布类似,其中TA1侧主要由β-Ti固溶体、FeTi和CuTi2化合物组成;Q235B侧主要由Fe,Cu基固溶体和Fe2Ti化合物组成.对接焊缝主要由Cu基固溶体,CuTi,FeTi,Cu4Ti,τ2和τ3金属间化合物组成,而搭接焊缝主要由Cu基固溶体、τ2和Cu4Ti组成.对接接头的平均硬度为449 HV0.1,搭接接头的平均硬度为335 HV0.1.

TA1/Q235B dissimilar butt and lap joints were obtained by tungsten inert gas(TIG)welding method with Cu-Cr-Co-Ni flux-cored wires.The microstructures of the joints were characterized by SEM,EDS and XRD.Microhardness tests were conducted to reveal the hardness distribution of the joints.The results showed that butt and lap welded joints were obtained without defects.Similar microstructures were observed in these two welded joints.Microstructure near TA1 interface consisted ofβ-Ti solid solution,FeTi and CuTi2 compounds,and microstructure near Q235B consisted of Fe and Cu solid solution and Fe2Ti compounds.The butt weld was composed of Cu solid solution,CuTi,Fe2Ti,Cu4Ti,τ2 andτ3 compounds.While in the lap joints,the weld was composed of Cu solid solution,τ2 and Cu4Ti compounds.The average hardness of the butt joint was 449 HV0.1,while that of the lap joint was 335 HV0.1.