采用光学显微镜、能谱仪、显微硬度计并结合宏观形貌观察等方法对G20Cr2Ni4A钢渗碳圆柱滚子的表面剥落原因进行了分析。结果表明: 由于圆柱滚子在渗碳、淬火后的表层组织中存在大量残余奥氏体和珠光体, 从而导致其表面强度和硬度下降, 并在外力作用下发生接触疲劳剥落;建议应保证淬火油的冷却能力, 并尽量缩短工件淬火转移时间;可考虑淬火后采取冷处理, 从而进一步减少工件表面的残余奥氏体含量。

Analysis on surface spalling of G20Cr2Ni4A steel carburizing cylindrical roller was studied by optical microscopy, energy dispersion spectroscopy, micro hardness testing and macrograph. The results show that the surface hardness and strength decreased were due to the excessive residual austenite and pearlite in cylindrical roller surface after carburizing and quenching, and then the contact fatigue spalling appearing at the action of outside force, so the cooling capacity of quenching oil should be ensured and quenching transfer time should be shorten as far as possible. Cold treatment following quenching might be adopted to further reduce the content of residual austenite on workpiece surface.