DX56D+Z镀锌超深冲钢常见表面缺陷分析

Analysis of Common Surface Defects of DX56D+Z Galvanized Ultra-deep Drawing Steel

鳞状起皮、表面凹槽、线痕状缺陷、边部翘皮是DX56D+Z镀锌板常见的表面缺陷。通过金相显微镜、扫描电镜、EDS能谱仪检测分析了几种常见缺陷的成因,并给出相应的措施。结果表明,氧化铝夹杂是导致鳞状起皮缺陷的主要原因,可通过控制连铸过程除氧剂的二次氧化降低此缺陷的发生率。钢板表面氧化铁皮是导致表面凹槽及连续线痕缺陷的主要原因,可通过控制酸洗工艺参数减少氧化铁皮残留,进而减少此类缺陷的发生。热轧工序中加热及保温系统的控制不当是造成钢板边部翘皮的根本原因,制定合理的加热工艺,增加边部保温设施,能有效减少边部翘皮缺陷的发生。

Scaly peeling, surface grooves, line-marking defects and edge warping are common surface defects of DX56D+Z galvanized sheet. The causes of several common defects were analyzed through metallurgical microscope,scanning electron microscopy and EDS component detection. And the corresponding measures were given. The results show that alumina inclusion is the main cause of scaly skin defects. The incidence of this defect can be reduced by controlling the secondary oxidation of the deoxidizer in the continuous casting process. The iron oxide scale on the surface of the steel plate is the main cause of surface grooves and continuous line marks defects. The residual oxide scale can be reduced by controlling the pickling process parameters, thereby reducing the occurrence of such defects. Improper control of the heating and insulation system in the hot rolling process is the root cause of the edge warping of the steel plate. Formulating a reasonable heating process and adding edge insulation facilities can effectively reduce the occurrence of edge defects.