汽车转向机蜗杆的热处理

Heat treatment of worm shaft for automobile steering system

以德系PQ35平台转向机蜗杆为例,对其技术要求和工艺难点进行了总结分析。并以37Cr S4钢蜗杆为研究对象,对其热处理过程进行实践研究。结果表明：采用调质＋去应力退火,即可得到强度和韧性兼备的材料基体,又能消除材料内部应力,大大减小了后续齿形滚压的变形量,保证了蜗杆的齿形精度和产品力学性能。

Based on the steering gear of the PQ35 platform of German system,the technical requirements and technical difficulties were summarized and analyzed,and the heat treatment process of 37 Cr S4 steel worm was studied. The results show that quenching and tempering plus stress relief annealing can be used not only to obtain a material matrix with good strength and toughness,but also to relieve the internal stress of the material,to reduce greatly the deformation of subsequent gear rolling,thus to ensure the gear shape accuracy and mechanical properties of the worm.