表面激光快速相变的硬化层特征

本文通过光镜、电镜及俄歇谱仪分析,表明四种钢铁材料的激光硬化层到基体存在一个深台阶的急剧过渡,硬度落差高达HV400～600,这是陡峭温度场分布的直接结果。硬化层的第二个特征是碳的局部扩散(10～30μm)。上述因素导致第三个特征,即多样化的组织分层以及相应的特征组织形貌,如球墨周围形成马氏体硬化环带、中碳钢内层出现不同碳浓度的马氏体区等。

The Features of Hardening Case in Laser Rapid-phase-transition

The features of Laser Hardening Case ( LHC ) has been examined with OM, EM and AES. It has been showed that, for four materials, there is a steep transition from inner hardening area to the core,hardness fall being HV 400-600. This is the result from steep temperature field distribution. As the second feature carbon atoms can diffuse locally to an extent of 10-30um. These can result in the third feature: there are complex sub-layers and corresponding characteristic microstructural morphology such as mar-tensite rings around graphite nodules and different martensite zones with different carbon content in the inner case of medium carbon steel and so on.