宝钢某热镀锌机组入口夹送辊辊面损伤原因分析及改进

Cause analysis and improvement on roll surface damage of inlet pinch roller of a hot galvanizing unit in Baosteel

本论文主要解决宝钢股份某热镀锌机组矫直机上夹送辊辊面损伤的问题。简要介绍了夹送矫直机的基本结构和工作原理,通过对夹送辊上辊面损伤一系列数据进行现场测绘和金相分析,辊子表面损伤的主要原因为辊子在使用过程中局部受到热冲击或者卡钢、粘钢使辊面局部组织发生了变化,组织应力导致辊面产生微小裂纹,继续使用过程中,裂纹扩展导致出现闭环状的裂纹缺陷。而导致卡钢、粘钢的主要原因,既与辊面硬度和带钢硬度差的原因有关,也与开卷时开卷机反向张力过大、夹送辊高负载工况下辊子打滑有关。本文对辊子结构进行改进,采用空芯辊,辊筒内壁进行车削,辊面采用聚氨酯;优化开卷机开卷时候的反向张力,减少开卷时各夹送辊马达负载,避免辊子打滑现象。改进后,夹送辊辊面损伤的问题得以很好的解决,提高了热镀锌机组夹送矫直机的稳定性和可靠性。

This paper mainly solves the problem of pinch roll surface damage of a hot dip galvanizing straightener unit in Baosteel. The basic structure and working principle of pinch straightener are briefly introduced. Through on-site mapping and metallographic analysis of a series of roll surface damage data on pinch roll, the main cause of roll surface damage is that the roll surface is partially impacted by thermal shock or the local structure of roll surface is changed by sticking steel or sticking steel. The structural stress leads to micro-cracks on roll surface and continues to be used. During the process, crack propagation results in a closed-loop crack defect. The main causes of steel sticking and sticking are not only related to the poor hardness of roll surface and strip steel, but also related to the excessive reverse tension of Uncoiler and roll slippage under high load condition of pinch roll. Improvement measures are as follows: Improving the structure of rollers, using hollow rollers, turning the inner wall of rollers and polyurethane roll surface;Optimizing the reverse tension of Uncoiler when uncoiling, reducing the load of each pinch roll motor when uncoiling, avoiding the phenomenon of roll slippage. After improvement, the problem of roll surface damage of pinch roll can be well solved, and the stability and reliability of pinch straightener of hot galvanizing unit are improved.