铜钨合金与低碳钢的焊接组织与性能

Microstructure and Properties of Welding Joint of Copper-Tungsten Alloy and Low Carbon Steel

用金相显微镜、扫描电镜、材料试验机、维氏硬度计等对铜钨合金与低碳钢焊接试样进行分析与检测。结果表明:焊缝组织为F+(ε+α)+λ,其中F为铁素体、λ(Fe2W)为金属间化合物、(ε+α)为颗粒状双相固溶体;(ε+α)双相固溶体与λ相的弥散强化作用,提高了焊缝及熔合区的强度与硬度。拉伸试验中,焊接接头只经过了弹性变形阶段和很短暂的塑性变形即被拉断,断口位于铜钨合金的熔合区,强度、塑性偏低。细小的孔隙和粗大空洞降低了焊接接头的强度,导致沿晶断裂。

Copper-tungsten alloy and low carbon steel welding samples were analyzed and tested by optical microscopy, SEM, tensile testing machine and Vickers hardness tester. The results show that the microstructure of the weld joint contains F＋（ε＋α）＋λ, where F is ferrite, λ（Fe2W） is intermetallic compound, and（ε＋α） is the granular binary phase solid solution;（ε＋α） phase solid solution and λ-phase dispersion strengthening effect improves the strength and hardness of the weld joint. The weld joint is pulled off after only a elastic deformation stage and a very short plastic deformation. The fracture of the weld joint is located in the fusion zone with lower strength and ductility. The strength of the weld joint is reduced because of the fine pores and coarse holes, resulting in intergranular fracture.