提高Q370qE钢板超声波探伤合格率的实践

为提高Q370qE钢板的超声波探伤合格率，取样分析了Q370qE钢板超声波探伤不合原因，结果表明其探伤不合格主要源于钢中非金属夹杂物、中心严重偏析所造成的钢板分层、连铸保护渣和耐火材料的卷入以及铸坯裂纹等。通过采取提高钢纯净度、改变夹杂物形态、控制浇注温度和拉速等措施后，钢板探伤合格率由75％提高到97％。

Practice of Increasing Ultrasonic Flaw Detection Qualified Rate on Q370qE Steel Plate

For increasing qualified rate of the ultrasonic flaw detection on Q370qE steel plate, defect position is sampied and analyzed. Result shows that unqualified rate of ultrasonic flaw detection mostly because of non-metallic inelusion involved in the steel plate, steel plate delamination eaused by center severity segragate, proteetion slags of eontinue casting and refractory engulfed in molten-steel, continue casting crack. After improving the molten-steel pureness degree, changing the non-metallic inclusion form, controlling the pouring temperature and pulling speed and so on, the ultrasonic flaw detection qualified rate is improved from 75% to 97%.