超高强度螺栓螺纹局部感应加热有限元分析与实践

Finite element analysis and practice of local induction heating on threads of ultra-high strength bolts

超高强度螺栓局部感应回火加热速度快、效率高,绿色环保,逐步取代传统的铅浴回火。但其存在线圈设计单一,工艺调节费时费力的现状,故基于COMSOL软件建立了一种螺纹局部回火加热的有限元分析模型,并通过试验结果的对比,验证了分析模型的正确性。同时通过对线圈设计和工艺过程的调整优化,大大减少了螺纹感应加热时的轴向和径向温度的不均匀性,并最终使超高强度螺栓螺纹部分的回火硬度满足回火标准要求。

Local induction tempering for ultra-high strength bolt with fast heating speed is high efficiency, green and environmental protection, and is gradually replacing the traditional lead bath tempering. However, the single coil design was time-consuming and labor-intensive in the process of adjusting, so a finite element model on local tempering heating of threads was built by COMSOL software. The correctness of the analysis model was verified by comparing with the experiment results. By adjusting and optimizing the coil design and process, the non-uniformity of axial and radial temperature during induction heating is greatly reduced, and ultimately the tempering hardness of the threaded part of the ultra-high strength bolt can meet the requirement of temper standard.