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采用单道搅拌摩擦搭接焊,实现了铜合金与不锈钢异种金属的焊接,在连铸结晶器用的Cu-Cr合金表面制备了304不锈钢过渡层。通过激光熔覆技术,在不锈钢过渡层表面制备了含有WC颗粒的镍基合金熔覆层。利用金相显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)和显微硬度计,对镍基合金熔覆层和过渡层的显微组织、物相构成和硬度进行了分析。结果表明,不锈钢过渡层与铜基体形成了可靠的连接,在焊合区中下部形成了均匀的钢-铜层状结构;在层状结构中形成了金属间化合物Ni Cu4,其硬度达337.26 HV;同时,镍基熔覆层组织致密,其强化相由γ-Ni、Ni3Fe、WC、W2C、和Cr23C6组成。显微硬度明显提高,平均显微硬度为485.0 HV,是铜合金基体的5.7倍。
The single-pass friction stir lap welding was adopted to achieve the welding of dissimilar metals between copper alloy and stainless steel. The 304 stainless steel transition layer was prepared on the surface of Cu-Cr alloy for continuous casting mold. The cladding layer of Ni-based alloy containing WC particles was prepared on the stainless steel transition layer by laser cladding. The microstructure and properties of Ni-based alloy cladding layer and transition layer were characterized by OM, SEM, EDS, XRD and microhardness tester Phase composition and hardness were analyzed. The results show that the stainless steel transition layer forms a reliable connection with the copper matrix and a uniform steel-copper layer structure is formed in the lower part of the welding zone. The intermetallic compound Ni Cu4 is formed in the layered structure and the hardness reaches 337.26 HV At the same time, the Ni-based cladding layer is dense and its strengthening phase consists of γ-Ni, Ni3Fe, WC, W2C and Cr23C6. Microhardness significantly increased, the average microhardness of 485.0HV, is 5.7 times the copper alloy matrix.