QT600球墨铸铁激光淬火相变层机械性能的研究

利用CO2激光对QT600球墨铸铁进行了淬火处理试验，对其金相组织、显微硬度和耐磨性进行了分析，并用X射线应力仪测定QT600激光淬火后的残余应力分布。试验结果表明，激光淬火后QT600的金相组织为隐品马氏体＋石墨，硬度为60—70HRC，耐磨性提高了46％，表面淬火相变层的残余应力均为压应力，其值在-250MPa以上，将有利于提高QT600材料的使用寿命。

Study on mechanical properties of phase transformation layer in QT600 nodular cast iron by CO2 laser quench

The surface of QT600 nodular cast iron is processed by CO2 laser quench. Mechanical properties such as metallographic structure, micro- hardness and wear resistance are analyzed, and the distributions of residual stress in the surface and section by laser quench sample are studied with X ray diffraction stress analyzer. The results shown that metallographic structures of TQ600 are aphanitic martensite and graphite, and their hardness is 60 - 70HRC, and wear resistance increases 46%, residual stresses of phase transformation layer are compressive, and its value is above - 250MPa, which is benefited to increase service life of QT6000.