DH36海洋平台用钢探伤不合格原因分析及工艺改进

Cause analysis of flaw detection disqualification of steel for DH36 offshore platform and process improvement

利用超声波探伤技术对轧制后的钢板进行了全面检测,系统性地分析了探伤不合格的原因。阐述了裂纹的成因,以及Nb、Ti等夹杂物来源,揭示了这些缺陷的微观结构和宏观表现。采用KR铁水脱硫:铁水采用全扒渣工艺,进站铁水目标硫的质量分数不大于0.005%,铁水温度不低于1340℃,转炉复合吹炼全程吹氩,终点碳成分控制在0.04%~0.06%,采用滑板挡渣操作,出钢时间不小于4 min等。这些措施的实施对于保障海洋平台用钢的安全性和可靠性具有重要意义,同时也为钢铁行业的质量控制提供参考。

Utilizing ultrasonic flaw detection technology,a comprehensive inspection was conducted on steel plates after rolling,and a systematic analysis was performed to identify the causes of flaw detection.The causes of cracks and inclusions result from Nb and Ti were elaborated,revealing the microstructures and maromorphology of these defects.Adopting KR hot metal desulfurization:The hot metal adopts a full slag removal process,with the incoming S less than 0.005%,hot metal temperature more than 1340℃,converter compound blowing throughout the process with argon,endpoint carbon content controlled between 0.04%-0.06%,utilizing a slide gate for slag retention,and a steel tapping time more than 4 minutes,etc.The implementation of these measures is vital for ensuring the safety and reliability of steel used in ocean platforms and contributes to quality control in the steel industry.