【摘要】 本文借助光学显微镜,透射电镜和扫描电镜,分析了HT20-40灰铸铁于激光熔化处理后表面显微组织特征,并探讨其形成原因。更多还原

【Abstract】 The microstructures of the laser hardened layer on the gray cast iron HT20--40 af-ter laser melting processing were examined by optical microscopy, transmission electron microscopy（TEM） and scanning electron microscopy （SEM）. Experimental results showed that a structurewith dendritic （M+A’） and interdendriticly iaminal transformed ledeburite （M+A’+Fe₃C） wasproduced after laser melting processing. The martensite was a mixture of dislocation martensite andtwin martensite. Dislocation pile-ups and twins were found to exist in the residual austenite.Microsegregation of composition and heterogeneity of microstructure were also apparent after lasermelting processing.更多还原