大型圆锥滚子轴承套圈碳氮共渗工艺优化  

Optimization of Carbonitriding Process for Large Size Tapered Roller Bearing Rings

作　　者：曾志鹏 周瑞虎 王帅 ZENG Zhipeng;ZHOU Ruihu;WANG Shuai(Xiangyang Automobile Bearing Co.,Ltd.,Xiangyang 441004,China;School of Mechanical Engineering,Hubei University of Arts and Science,Xiangyang 441053,China)

机构地区：[1]襄阳汽车轴承股份有限公司,湖北襄阳441004 [2]湖北文理学院机械工程学院,湖北襄阳441053

出　　处：《轴承》2024年第6期91-96,共6页Bearing

基　　金：襄阳市科技计划资助项目(2021AAH004413);湖北省技术创新计划重点研发专项项目(2023BAB132)。

摘　　要：碳氮共渗工艺可以大幅提升轴承疲劳寿命,但在商用车轮毂轴承上的研究还较少。采用工艺试验的方法,分析对比不同温度、碳势、NH_(3)流量和工艺时间对33022圆锥滚子轴承的渗层深度和表面硬度的影响,得到了最佳工艺参数:强渗阶段,温度为860℃,NH_(3)流量为2.5 L/min,碳势为1.2%,时间为330 min;扩散阶段,温度为860℃,NH_(3)流量为2.5 L/min,碳势为1.0%,时间为60 min;保温阶段,温度为820℃,NH_(3)流量为2.5 L/min,碳势为1.0%,时间为60 min。工艺优化后,测量碳氮共渗后的轴承尺寸、表面组织和硬度,均能满足产品技术要求;轴承疲劳试验结果表明,相比于常规马氏体淬回火热处理工艺,碳氮共渗处理后的轴承寿命由2L_(10)提升至5L_(10),有效提高了轴承的疲劳寿命。Carbonitriding can significantly improve the fatigue life of bearings,but there are few researches on hub bearings for commercial vehicles.By using the method of process test,the effects of different temperatures,carbon potential,NH_(3) flow rate and process time on depth of infiltration layer and surface hardness of 33022 tapered roller bearings are analyzed and compared.The optimal process parameters are obtained:during strong infiltration stage,the temperature,NH_(3) flow rate,carbon potential and time are 860 ℃,2.5 L/min,1.2%,330 min respectively;during diffusion stage,the temperature,NH_(3) flow rate,carbon potential and time are 860 ℃,2.5 L/min,1.0%,60 min respectively;during holding stage,the temperature,NH_(3) flow rate,carbon potential and time are 820 ℃,2.5 L/min,1.0%,60 min respectively.After process optimization,the measured size,surface microstructure and hardness of the bearing rings carbonitrided can meet the technical requirements of products;the fatigue test results of the bearings show that compared with conventional martensite quenching and tempering heat treatment process,the life of the bearings after carbonitriding is increased from 2L_(10) to 5L_(10),effectively improving the fatigue life of the bearings.

关 键 词：滚动轴承 圆锥滚子轴承 表面热处理 碳氮共渗 优化 

分 类 号：TH133.33[机械工程—机械制造及自动化] TG156.8[金属学及工艺—热处理]