不同表面状态对齿轮气体渗氮的影响

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Abstract： Through experimental investigations on the influence of different surface conditions of quenched and tempered 42CrMo gear steel on gas nitriding，the following conclusions were drawn： To simulate the surface roughness of ground gear teeth，specimens were subjected to grinding and polishing，resulting in the lower nitrided case depth and surface hardness at 0.679mm and 672.27HV0.3 ，respectively; Increasing the surface roughness within acertain range enhanced the nitrided case depth.At a surface roughness of 2.43μm ，the case depth and surface hardness reached 0.839mm and 733.06HV0.3 ，representing increases of 23.6% and 8.1% ，respectively，compared to the polished specimens; Subjecting polished surfaces to intensive shot peening prior to nitriding improved the nitrided case depth，achievingvalues of 0.79mm and 691HVo.3， corresponding to increases of 16.3% and 1.9% over the polished specimens;Acid etching the polished surfaces before nitriding significantly increased the case depth to 0.866mm （a 27.5% improvement） and the surface hardness to 752HV0.3 （a 10.9% increase）; Furthermore， finer and more uniform quenched and tempered microstructure，along with higher matrix hardness，contributed to greater nitrided case depthand higher surface hardness.A 14.4% increase in the matrix hardness led to improvements of

11.3% innitrided case depth and 3.9% in surface hardness. Keywords：gasnitriding;surface condition; gear

1 序言

渗氮属于齿轮表面硬化工艺中的一种化学热处理方法，采用中碳合金钢制造的齿轮经调质预备处理后实施渗氮处理，其表面硬度可提升至 500～ 1200HV ，有效提高齿面的耐磨性和抗咬合性能。（剩余3427字）