摘要
针对迁钢生产的汽车用冷轧超低碳钢来料碎边缺陷严重且发生率高达30%,经冷轧后出现严重毛刺缺陷,不易打磨干净,在连退炉区脱落导致铁屑粘附在炉辊上形成结瘤,造成周期性的硌印缺陷,严重影响汽车板表面质量的问题,通过缺陷微观分析,发现缺陷周围存在大量氧化质点及铜元素富集情况,可将缺陷追溯于板坯加热前,即铜元素在板坯表层析出和富集是造成碎边缺陷的根本原因;结合火焰清理(简称机清)板坯产品缺陷发生率高达30%,而非机清板坯产品无此缺陷的宏观规律,对机清板坯质量及机清设备开展检查,得到碎边缺陷产生原因为:板坯机清时侧面烧嘴间隙铜箔局部烧损导致铜元素渗入板坯侧面,产生“铜脆”类缺陷而导致。通过对机清烧嘴管控及对热轧工序加热及除鳞工艺优化等措施,有效解决了碎边缺陷。
Aiming at the problem of severe edge-cracking defects of ultra-low carbon steel hot rolled strips for cold rolled sheets of automotive produced by Qiansteel,where the occurrence rate is as high as 30%.The severe burr defects would appeared after cold rolling and difficult to polish clean lead to iron chip adhesion on furnace of rolls in the continuous annealing furnace area,and it formed scale tumors and caused periodic indentation defects that seriously affect the surface quality of automotive sheets.Through microscopic analysis of the defects,a large number of oxide particles and copper element enrichment were found around the defects,tracing the root cause could be backed to before slab heating,i.e.the precipitation and enrichment of copper elements on the slab surface were the fundamental cause of the edge-cracking defects.Combining the macroscopic law that the occurrence rate of edge-cracking defects in flame-cleaned(abbreviated as mechanical cleaning)slabs is as high as 30%,while non-mechanical cleaning slabs show no such defects,inspections on the quality of mechanical cleaning slabs and mechanical cleaning equipment were conducted.It was determined that the root cause of edge-cracking defects is the local burning damage of copper foil in the narrow-face burner gap during mechanical cleaning of slabs,leading to copper element infiltration into the narrow face of the slab and inducing"copper embrittlement"-type defects.Effective solutions to the edge-cracking defects were achieved through measures such as controlling mechanical cleaning burners and optimizing the heating and scale removal processes in the hot rolling process.
作者
焦会立
杨莹莹
李奕
裴兴伟
倪有金
关建东
JIAO Huili;YANG Yingying;LI Yi;Pei Xingwei;NI Youjin;GUAN Jiandong(Beijing Shougang Co.,Ltd.,Tangshan 064404,China)
出处
《轧钢》
北大核心
2025年第4期151-155,168,共6页
Steel Rolling
关键词
超低碳钢
热轧带钢
碎边缺陷
板坯
机清
铜脆
ultra-low carbon steel
hot rolled strip
edge-cracking defect
slab
mechanical cleaning
copper embrittlement
