SG45圆钢超声波探伤不合格原因分析及工艺改进

Analysis on Disqualification Causes and Process Improvement of SG45 Round Steel in Ultrasonic Flaw Detection

通过便携式超声波探伤仪、金相显微镜、扫描电镜和直读光谱仪对大规格SG45圆钢超声波探伤不合格原因进行分析。结果表明,圆钢超声波探伤不合格是由于圆钢心部存在组织偏析。通过调整连铸电磁搅拌参数、轻压下工艺和连铸坯缓冷,同时优化轧制工艺可以提升大规格SG45圆钢超声波探伤合格率。

The unqualified cause of ultrasonic flaw detection for large-size SG45 round steel was analyzed by portable ultrasonic flaw detector,metallographic microscope,scanning electron microscope and direct reading spectrometer.The results showed that the unqualified ultrasonic flaw detection of SG45 round steel was due to the structural segregation in the core of the round steel.By adjusting continuous casting electromagnetic stirring parameters,light reduction process,slow cooling of continuous casting billet and optimizing rolling process,the the qualified rate of ultrasonic flaw detection for large-size SG45 round steel can be improved.