精密齿轮件的真空低压渗碳高压气淬热处理

Vacuum low pressure carburizing and high pressure gas quenching heat treatment of precision gear

采用真空低压渗碳和高压气淬相结合的工艺代替以往的气氛渗碳和油淬工艺,在WZST-60G双室真空渗碳设备上进行SCM420精密齿轮的热处理工艺研究,并对其显微组织、硬度、表面碳浓度、变形量等重要工艺指标进行分析。结果表明:930℃渗碳后,在830℃进行2.0 MPa高压气淬,经160℃回火后,齿轮碳化物等级为1级,表面硬度可达60 HRC,变形量小于0.04 mm,完全符合工艺要求。

The heat treatment technology of SCM420 precision gear was studied on WZST-60 G double-chamber vacuum carburizing equipment by using vacuum low pressure carburizing and high pressure gas quenching,instead of the previous process of atmosphere carburizing and oil quenching.The important technological indexes such as microstructure,hardness,surface carbon concentration and distortion were analyzed.The results show that after vacuum carburized at 930℃,2.0 MPa high-pressure gas quenching at 830℃and tempered at 160℃,the SCM420 gear fully meets the technical requirements,with gear carbides grade 1,surface hardness up to 60 HRC,distortion less than 0.04 mm.