Q420GJD探伤不合格原因分析及改进措施

Reasons analysis of Q420GJD flaw detection unqualified and improvement measures

本文对普阳钢铁3500 mm热轧线生产的25 mm厚Q420GJD钢板探伤不合格的原因进行了研究。采取对钢板探伤不合格部位取样,并利用金相显微镜、扫描电镜、能谱仪等检测手段对钢板探伤不合格部位的微观结构形态和夹杂物进行分析,同时结合实际生产工艺,找到钢板厚度1/2处探伤不合格的原因。通过优化转炉冶炼、调整精炼渣成分组成、连铸保护浇铸、高温缓冷和定期维护剪刃等技术管理改进措施,提高了钢板探伤合格率。

In this paper,the causes of the 25 mm thick Q420GJD steel plate flaw detection unqualified produced by Puyang iron and steel company 3500 mm production line were studied.Taking sampling the flaw detection unqualified parts of steel plate,and the microstructure morphology and inclusions of the steel plate unqualified parts were analyzed by metallographic microscope,scanning electron microscope and energy spectrometer,at the same time,combined on the actual production process,the reasons of flaw detection unqualified at a half thickness of steel plate were found.Through adopting technical management measures such as optimization of converter smelting,adjustment of the composition of refining slag,protective casting of continuous casting,high temperature and slow cooling,and regular maintaining blade of scissors,the flaw detection inspection qualified rate of steel plate was improved.