用EBSD方法分析汽车板表面点缺陷的产生原因  

Root cause analysis of tiny spot defects on zinc coated steel sheets using EBSD

作　　者：洪巨锋 金鑫焱[1] HONG Jufeng;JIN Xinyan(Research Institute,Baoshan Iron&Steel Co.,Ltd.,Shanghai 201999,China)

机构地区：[1]宝山钢铁股份有限公司中央研究院,上海201999

出　　处：《宝钢技术》2024年第6期23-29,共7页Baosteel Technology

摘　　要：以3个分别由基板纵向擦伤、横向擦伤及麻点引起的镀锌汽车板表面微小点缺陷为研究对象,采用电子背散射衍射(EBSD)技术重点表征了基板表面对应缺陷的晶体结构信息,利用晶粒尺寸、大小角度晶界、亚晶及应变分布等特征,有助于确定缺陷产生的工艺单元。在3个缺陷的截面上,除正常再结晶晶粒外,EBSD还观察到了位于再结晶晶粒内部的小角度晶界亚晶,局部大角度晶界细晶或粗晶、残余应力分布等微观特征。说明基板上的擦伤或麻点缺陷发生后,周围组织仅发生了高温回复现象,因此判断3个缺陷均发生在带钢连续退火机组的均热尾段至缓冷段。Three types of tiny spot defects on zinc coated automotive steel sheets,which were caused by longitudinal scratches,transverse scratches,and dents on substrate,respectively,were characterized using electron backscattered diffraction(EBSD)technology.The crystal structure characteristics of the corresponding defects on the substrate,including grain size,low and high angle grain boundaries,sub-grain,and strain distribution,help to determine the process unit where the defects occurred.In addition to normal recrystallized grains,low angle grain boundary sub-grains located inside recrystallized grains,and residual stress were observed on the cross sections of the three defects,indicating that only high-temperature recovery occurred after the defects on the substrate formed.Therefore,it is determined that these three defects all occurred from the end of soaking to slow-cooling unit in the continuous annealing line.

关 键 词：EBSD 点缺陷 亚晶 残余应力 

分 类 号：O657.31[理学—分析化学]