焊瓶钢HP295表面黑线缺陷分析与质量控制

Analysis and quality control of surface black line defect of welded bottle steel HP295

针对客户反馈的焊瓶钢HP295表面存在黑线缺陷导致在冲压后产生褶皱的质量问题,本文介绍了气瓶生产的主要工艺流程,阐述了焊瓶钢HP295的材料及轧制过程,对黑线缺陷的形态特点及冲压加工后表面褶皱情况进行了实物说明,并通过金相组织分析、能谱分析和对比分析的手段研究了焊瓶钢HP295表面黑线缺陷的产生原因。结果表明:检验分析中的焊瓶钢HP295钢板表面黑线为轧制早期产生的缺陷在过轧制过程中经碾压后体现为黑线,主要由于异物压入和铸坯上存在表面裂纹、皮下气泡和孔洞等缺陷引起。结合生产厂实际控制情况,通过组织协同优化,在炼钢工序控制铸坯表面质量和热轧工序做好清洁生产维护和设备精度管控等措施,有效控制HP295表面黑线缺陷的发生率,总缺陷率由攻关前的2%控制在用户可以接受的千分之三以内,满足了客户的使用要求。

According to the customer feedback,the black line defect on the surface of welding bottle steel HP295 leads to the wrinkle after stamping.This paper introduces the main technological process of gas bottle production,expounds the material and rolling process of welding bottle steel HP295,describes the morphological characteristics of black line defect and the surface wrinkle after stamping,and studies the causes of black line defect on the surface of welding bottle steel HP295 by means of metallographic analysis,energy spectrum analysis and comparative anal-ysis.The results show that the black line on the surface of HP295 steel plate of welding bottle steel in inspection and analysis is a defect produced in the early stage of rolling,and it is reflected as black line after being rolled in the process of over-rolling,which is mainly caused by foreign bodies pressing in and defects such as surface cracks,sub-cutaneous bubbles and holes on the billet.Combined with the actual control situation of the production plant,the oc-currence rate of black line defects on the surface of HP295 was effectively controlled by organizing collaborative op-timization,controlling the surface quality of billet in steelmaking process,cleaning production maintenance and e-quipment precision control in hot rolling process,and the total defect rate was controlled within three thousandths acceptable to users from 2%before tackling key problems,which met the use requirements of customers.