热浸镀镍基合金层加热重熔前后的组织结构

Microstructure of Hot-Dipping Nickel-Base Alloy Coatings before and after Heated Refusion

热浸镀镍基合金层结合力、耐磨性差,加热重熔可改变镀层组织结构进而改善其性能。在碳钢基体表面热浸镀镍基合金,并对镀层加热重熔,研究了热浸镀层加热重熔前后的组织结构。结果表明:加热重熔后热浸镀镍基合金层组织中树枝状共晶体消失,不连续的Cr的硼化物硬质相弥散分布在镍基固溶体中,为提高镀层的耐磨性提供了很好的保证,且镀层与基体之间存在明显的扩散过渡带,形成了很好的冶金结合。

Ni-base alloy coatings were prepared on the surface of carbon steel by hot dipping.Resultant hot-dipping Ni-base alloy coatings were subjected to heated refusion,and the microstructure of the coatings before and after heated refusion was comparatively analyzed.It was found that the dendritic eutectics in the Ni-base alloy coatings disappeared after heated refusion,and discontinuous hard phases of chromium borides were diffusely distributed in Ni-base solid solution,thereby increasing the wear resistance of the carbon steel.Besides,an obvious diffused transition layer existed at the interface of the coatings and substrate,and the coatings were well adhered to the steel substrate via metallurgical bonding.