大规格轴承钢盘条冷拔过程探索与实践

Exploration and practice of large size bearing steel wire rod drawing process

特殊钢冷拉钢棒的精度要求越来越高。影响拉拔过程的主要因素有原料强度、压缩率、拉拔模角度、拉拔模定径带长度、拉拔速度等,给出拉拔模定径带长度与模孔直径之间的关系。以大规格轴承钢盘条为例,分析5个因素对拉拔应力及拉拔表面精度的影响,提出改进意见,以提高拉拔模使用寿命和生产效率,获得好的成品精度和表面质量。对于Φ6.0~25.0 mm的轴承钢冷拔材,冷拔前应进行球化退火,拉拔减径尺寸一般为0.5~2.0 mm,总压缩率在4%~20%,模孔角度选用14°~16°,定径带长度为3.5~6.5 mm,拉拔速度为30~50 m/min,优化后的工艺能够较好满足冷拔成品的性能及表面质量要求。

The precision demand of cold drawn steel bar is higher and higher. The main factors influencing the drawing process are as follows： raw material strength,compression ratio,drawing die angle,sizing zone length,drawing speed,etc,the relationship between the sizing zone length and the die hole diameter is given. To take large size bearing steel wire rod as example,the influence of five factors on drawing stress and drawing surface precision is analyzed,improving suggestions are put forward,in order to improve the service life of drawing die and production efficiency,and achieve good finished product precision and surface quality. The diameter 6. 0 ~ 25. 0 mm bearing steel cold drawn material should be spheroidizing annealing treated before cold drawing,drawing reducing size is 0. 5 ~ 2. 0 mm,the total compression ratio is4% ~ 20%,die angle is chosen 14° ~ 16°,sizing zone length is 3. 5 ~ 6. 5 mm,drawing speed is 30 ~ 50 m / min,the optimized process can better meet the performance of cold drawing finished product and requirements of surface quality.