【摘要】 研究球墨铸铁、灰铸铁和可锻铸铁激光熔融处理后存在于熔化区和半熔化区的残存石墨（即球状、片状和团絮状石墨）周围的双壳层组织．同时指出，在近灰铸铁激光熔池的相变硬化区中片状石墨周围马氏体量的不均匀分布情况。最后，提出了形成这些组织的机制。更多还原

【Abstract】 This paper puts mainly stress on the double-shell structure around the residual graphite (i. e. spheroidal, flake and temper-carbon graphite) of nodular cast iron,grey cast iron and malleable cast iron in the remelted zone and semi-remelted zone.It be also reported that there exists the heterogeneity of martensitic volume fraction around the flake graphite in the transformation hardening zone near the remelted pool. Meanwhile, the mechanisms of formation of these kinds of structure have been proposed.更多还原