热连轧单机架粗轧机中间坯侧弯废钢成因及对策

Causes and Countermeasures of Side Bending Scrap of Middle Billet in Single Stand Roughing Mill of Hot Continuous Rolling Mill

热连轧单机架粗轧机在轧制中,由于板坯往复轧制道次多,轧件长度长,出现奇偶道次侧弯方向相反和"S"弯,轻则造成带钢楔形超标或头尾轧烂,重则产生中间坯头部弯撞击轧机前后边板和热卷箱前侧导板,产生废钢,影响到轧制的稳定。文章分析了辊系交叉出口轧件侧弯运动和轧制力偏差波动趋势以及辊系水平交叉及垂直系异常的原因,现场通过对轧机牌坊修复、辊型优化、调整工艺参数等,因侧弯造成废钢问题得到有效控制,带钢楔形超标大幅降低,提高了产线成材率和板形质量。

In the rolling process of single stand roughing mill of hot strip mill,due to many reciprocating rolling passes of slab and long rolling piece length,side bending direction of odd and even passes is opposite and s bending occurs,which may cause strip wedge exceeding standard or head and tail rolling rotten,or head bending of intermediate slab impacting front and rear side plate of mill and front guide plate of hot coil box,resulting in scrap and affecting rolling stability.This paper analyzes the fluctuation trend of side bending movement and rolling force deviation of cross roll exit,as well as the causes of abnormal horizontal cross and vertical roll system.Through the repair of mill housing,roll profile optimization and adjustment of process parameters,the scrap problem caused by side bending is effectively controlled,the strip wedge exceeding the standard is greatly reduced,and the yield and shape quality of the production line are improved.