摘要
利用光学显微镜和透射电镜对孕育铸铁激光硬化层进行结构分析,并对经激光处理后孕育铸铁的耐磨特性进行了系统的测试。结果表明:激光淬火带的纵剖面呈月牙形,熔化区位于月牙中部,其组织是由莱氏体构成,周围为相变硬化区,区内的组成相计有:片状石墨、残余奥氏体和马氏体(包括片状马氏体和枣核马氏体)。激光硬化层的耐磨性极佳,和未经激光处理的试样相比,局部激光处理后试样的磨损量可大大降低,其原因可用激光硬化层内各组成相的性态及它们对磨损机制的影响来解释。
The laser hardened layer of a modified grey cast iron was
analysed by optical and TEM microscopy,and the wear resistance of the cast
iron after laser hardening was tested systematically.The profile of laser
hardened band is crescentlike.Melting zone is located at the center of the
hardened band and the microstrueture of the zone consists of ledeburite and the
surrounding transformation hardened zone consists of plate graphites,martensites
and retained austenites.Laser hardened band is excellently wear resistant.
The cause of its high wearability can be explained by the effect of
microstructural factors on wear mechanism.
