20CrMoH钢齿轮渗碳淬火组织粗大的原因分析及预防措施

Analysis and preventive measures for the coarse microstructure of 20CrMoH steel gears after carburizing and quenching

对20CrMoH钢齿轮经渗碳淬火、回火后粗大组织进行了综合分析,从预防原材料成分偏析严重、奥氏体晶粒粗大、控制齿轮锻造温度,以及优化渗碳淬火工艺等多方面提出了改进措施。通过控制原材料带状偏析2.5级以内、奥氏体晶粒度5级以上,锻造温度950~1080℃,增加等温正火,以及采取≤920℃渗碳淬火工艺,从而有效地消除了齿轮渗碳淬火、回火后的粗大组织。

This article comprehensively analyzes the coarse microstructure in 20CrMoH steel gears after carburizing,quenching,and tempering,improvement measures have been proposed from multiple aspects,including preventing severe segregation of raw material components,coarsening austenite grains,controlling gear forging temperature,and optimizing carburizing and quenching processes.By controlling the strip segregation of raw materials within 2.5 levels,austenite grain size above 5 levels,forging temperature between 950~1080℃,adding isothermal normalizing process,and carburizing below 920℃,the coarse structure of gears after carburizing,quenching,and tempering is effectively eliminated.