激光合金化过渡区显微结构的观察

OBSERVATION ON MICROSTRUCTURE OF LASER MELTED TRANSITION ZONE

本文采用EPMA,AES和SEM技术,观察到Fe-Ni-Cr合金涂层和45号钢基体激光合金化后,其熔化区和热影响区之间的过渡区,存在明显的化学不均匀性特征,高温回火时尤为严重,以致形成过渡区一侧脱碳,而熔化区一侧增碳的现象。

The surface alloying specimen was made of the steel 45 substrate overcoating byoxygen-acetylene flame spraying Fe-Ni-Cr alloy powder and laser remelted. The chemical heter-ogeneity was clearly observed on the transition zone between the laser melted zone and heat-affected zone by means of EPMA, AES and SEM. This heterogeneity is rather serious duringhigh temperature tempering, so the decarburization on the transition zone side and the recarbu-rization on the melted zone side were found.