冷轧薄窄规格低碳钢碎边浪板形问题研究  

Study on the broken edge wave problem of cold rolled thin and narrow gauge low carbon steel strip

作　　者：李硕 于洋 宋浩源 马家骥 李明远 武巧玲[2] LI Shuo;YU Yang;SONG Haoyuan;MA Jiaji;LI Mingyuan;WU Qiaoling(Technology Institute of Shougang Group Co.,Ltd.,Beijing 100043,China;Shougang Co.,Ltd.,Beijing 100043,China)

机构地区：[1]首钢集团有限公司技术研究院,北京100043 [2]首钢股份有限公司,北京100043

出　　处：《轧钢》2024年第2期69-77,共9页Steel Rolling

摘　　要：随着冷轧产品规格的拓展,冷轧机组的板形控制能力面临极大压力和挑战。针对行业内较难解决的低碳钢薄窄规格碎边浪问题,以某冷轧厂1970 mm酸轧机组带钢板形为研究对象,试验和仿真结合对该问题进行了研究。结果表明:薄窄规格碎边浪缺陷是在上游机架产生,并在下游机架缺陷板形逐渐被消化遗传到出口形成的。碎边浪的产生原因:一方面由于低碳钢精轧过程中边部温降过快容易导致边部粗晶,使得边部相较于中部硬度低约15HRB;另一方面由于轧制薄规格带钢的过程中工作辊会产生更大的挠曲和弹性压扁,且宽幅轧机轧制窄规格带钢过程中轧机对辊缝凸度的调节能力有限,使得薄窄规格带钢更容易发生局部延伸不均。为此,针对全流程提出了改善碎边浪的一系列措施,包括设计边部带锥度的工作辊辊形以及VCL支撑辊辊形以减少边部区域金属的延伸,降低五机架轧机轧制力以提高对碎边浪的消化能力,对酸轧入口带钢进行切边处理或采用边部加热工艺以改善边部、中部组织性能均匀性等措施。试验结果表明:采用边部加热工艺相较于增大装钢间隙(至200 mm)、提高终轧温度(10℃)等措施对改善带钢宽度方向温度分布均匀性效果显著,冷轧带钢板形IU值降低43%,改善效果与冷轧前进行切边处理相当。将优化措施在现场固化后,厚度0.8 mm、宽度1250 mm以下薄窄规格带钢碎边浪缺陷发生率由40%降至0.5%,板形控制水平在1 IU左右。With the enrichment of cold rolling products and specifications,the shape control ability of cold rolling mill is facing great pressure and challenge.Aiming at the problem of broken edge wave of thin and narrow gauge low carbon steel strip,which is difficult to solve in the industry,experimental and simulation studies were conducted on the strip shape of a 1970 mm tandem cold rolling mill.The results indicate that the broken edge wave is generated in the upstream stands,gradually digested in the downstream stands,and ultimately inherited to the outlet.The reason for the generation of broken edge wave:on the one hand,in the process of hot finishing rolling of low carbon steel,the edge temperature drops too fast,resulting in coarse grains at the edge,which makes the edge hardness about 15HRB lower than that in the middle.On the other hand,the ability of wide rolling mill to control roll gap crown is limited in the narrow strip rolling process,and the difference of roll elastic flattening degree at the edge and middle of the strip,both are the causes of the problems.Then,a series of measures to improve the broken edge wave are put forward,including designing the work roll contour with taper at the edge and VCL backup roll contour to reduce the extension of strip in the edge area,reducing the rolling force of five stands mills to improve its ability to digest broken edge wave,trimming at the inlet of acid rolling or adjusting the hot rolling process to improve the uniformity of microstructure uniformity.The experimental results indicate that the superimposed use of edge heating has a significant improvement effect,and the shape IU value is reduced by 43%.After the application of optimization measures,the occurrence rate of strip shape with thickness smaller than 0.8 mm and width smaller than 1250 mm is reduced from 40%to 0.5%,and the control level of strip shape is about 1 IU.

关 键 词：冷轧薄窄规格带钢 碎边浪 组织均匀性 辊缝凸度 辊形 边部加热 

分 类 号：TG335.12[金属学及工艺—金属压力加工]