20CrMnTi碳氮共渗异常组织的分析及防止措施

Analysis and Prevent Measures on 20CrMnTi Carbonitriding Abnormal Microstructures

20CrMnTi钢制汽车变速齿轮在碳氮共渗时表层出现黑色组织,严重时使齿轮表面硬度、接触疲劳和弯曲疲劳强度大幅下降,造成齿轮早期失效,严重降低工作寿命。为此,对该黑色组织产生的原因进行了分析,并提出改进与防止措施。对齿轮的生产起到指导作用。

Black microstructures generated in the surface of the carbonitrided gear when 20CrMnTi steel was used. The surface hardness, contact fatigue and bending fatigue strength of the gear were decreased significantly, which caused the failure of the gear in the early stage and reduced its working life. In the present article, the formation of the black microstructures was analyzed. The improvement and preventive measures were proposed, which played guidance for the production of gears.