无取向电工钢热轧楔形问题分析与控制

Analysis and control of strip wedge of non-orientation electrical steel in hot rolling process

电工钢板形质量要求严苛,无取向电工钢热轧生产中存在的较大楔形,给冷轧等后工序生产带来了严重的困难,成为制约电工钢产品质量的重要因素。首先通过中间坯断面形状测量统计、红外热像观测和轧辊磨损测量等方法对电工钢热轧楔形问题进行分析,然后通过基于电工钢实际材料模型的有限元仿真分析来料楔形、轧辊不均匀磨损和单相区以及两相区温度不均匀分布等因素对轧后带钢楔形的影响。分析结果发现,来料楔形在后续对称轧制条件下可减小但很难完全消除;工作辊磨损倾斜对楔形的影响比支撑辊更大;横向温度倾斜对楔形的影响最大,较小的横向温差即引发巨大楔形,两相区轧制时横向温度倾斜引发的楔形比单相区大。基于以上研究,针对性地提出无取向电工钢楔形控制措施,并分析控制效果。

High quality of the strip profile of electrical steel is demanded. Large wedge of non-orientation electrical steel strip in hot rolling process have brought serious difficulties to the cold rolling and other subsequent processes, and has become an important factor restricting the quality of electrical steel products. The strip wedge of electrical steel was analyzed by means of the measurement statistics of the strip profile of the intermediate slab, the observation of infrared thermography and the measurement of the worn rolls, etc. Then the effects of inlet wedge, uneven wear of rolls, inhomogeneous temperature distribution of the plate in mono-phase region and double-phase region on the wedge after rolling were investigated by a finite element(FE) model based on the actual material model of electrical steel. The calculation results indicated that the wedge existed in the slab can be decreased but it was difficult to be eliminated during afterwards rolling. The effect of work roll slant wear on the wedge was greater than that of backup roll. The slant distribution of transverse temperature had a leading effect on the strip wedge, and the smaller transverse temperature difference could cause the huge wedge. Especially, the wedge generated in double-phase region was larger than that in single-phase region with the same temperature difference. Based on the above investigations, the control measures were put forward to reduce the strip wedge and their effects were analyzed.