Wang Liuping, Ni Zhengshun, Xiao Yingang, Li Yongqiang, Liu Xianghuan, Chen Yongzhi, Cui Shuanghao, Zhang Dejun, Mi Chengji, He Quanguo
College of Mechanical Engineering, Hunan University of Technology, Zhuzhou 412007, China.
Laser Welding Department, Zhuzhou Gear Co., Ltd., Zhuzhou 412007, China.
Materials (Basel). 2023 Jun 29;16(13):4721. doi: 10.3390/ma16134721.
In order to avoid slackening of differential housing and gear joined by bolts, the laser-welding process is proposed in this paper, and the strength of a connecting joint was estimated by numerical analysis with consideration of welding residual stress. The process parameters of laser welding for dissimilar materials QT600 cast iron and 20MnCr5 structural alloy steel were introduced, and chemical composition analysis and microstructure analysis were conducted on the welded joints. The finite element model of laser-welded differential housing and gear was established to obtain the welding residual stress by applying a moving heat source. To verify the accuracy of the simulated result, static pressing tests were employed. The maximum tensile residual stress was 319.4 MPa, located at the same point as the maximum temperature. The simulated stress agreed well with the experimental data. Finally, the dynamic strength of laser-welded differential housing and gear under forward, reverse, and start-up conditions was assessed by regarding welding residual stress as the initial stress field, which showed that all safety factors were greater than 1.4.
为避免通过螺栓连接的差速器壳和齿轮出现松动，本文提出了激光焊接工艺，并通过考虑焊接残余应力的数值分析来评估连接接头的强度。介绍了QT600铸铁和20MnCr5结构合金钢异种材料激光焊接的工艺参数，并对焊接接头进行了化学成分分析和微观结构分析。建立了激光焊接差速器壳和齿轮的有限元模型，通过施加移动热源来获得焊接残余应力。为验证模拟结果的准确性，进行了静压试验。最大拉伸残余应力为319.4MPa，位于与最高温度相同的点。模拟应力与实验数据吻合良好。最后，将焊接残余应力视为初始应力场，评估了激光焊接差速器壳和齿轮在前进、后退和启动条件下的动态强度，结果表明所有安全系数均大于1.4。
