冷轧TRIP980钢表面色差成因分析与控制

针对冷轧TRIP980钢表面色差缺陷,采用SEM、XRD等手段分析缺陷成因.结果表明:连续退火后板面色差位置呈现表层碎裂的形貌;能谱分析表明,与正常位置相比,缺陷位置存在明显的0元素峰,表现为Si、0元素的显著富集,与轧硬板的分析结果一致;XRD分析表明,热卷表面形成红色铁皮的原因是铁橄榄石类粘性氧化铁皮未能有效去除,...

Cause analysis and control on surface color difference for cold-rolled TRIP980 steel

For surface color difference defects on cold-rolled TRIP980 steel,the causes of defects were analyzed through SEM and XRD methods. The results show that the area with color difference defects show the surface broken topography after continuous annealing.Through energy spectrum analysis,compared with normal position,an obvious O element peak is found and there is significant enrichment of Si and O elements in defect position,which is consistent with the analysis result of cold-rolled plate. Through XRD analysis,it is showed that the reason for red scales on the surface of hot coil is that the olivine cannot be removed effectively,resulting in the formation of Fe₂O₃ in subsequent rolling process. Broken topography on surface is formed after cold rolling because the red scale defect is difficult to be wiped off by pickling. After continuous annealing,the color contrast in the defect and normal areas increase to result in color difference defects finally because the reducing atmosphere and high temperature lead the enrichment of Si and Mn. Thus color difference defects after continuous annealing are the results of several processes,such as hot rolling and acid rolling. Based on the analysis of color difference defects,by optimizing the heating process of slab and enhancing the descaling effect and pickling ability,the color difference defect is controlled effectively.