热轧特厚钢板探伤不合原因分析

Analysis on Unqualified Causes of Hot Rolled Extra-heavy Steel Plate by Ultrasonic Flaw Detection

对厚度70 mm以上探伤钢板缺陷进行分类、取样,通过金相检验及扫描电镜等手段对缺陷进行了分析。结果表明,探伤不合的主要原因是缩孔和疏松、三角区裂纹及应力裂纹。

The defects on the surface of extra-heavy steel plates with thickness over 70 mm are classified and then sampled.Then the defects are examined and analyzed by means of macroscopic and metallographic examination together with scanning electron microscope（SEM）.The results show that the failure of flaw detection is caused by contraction cavities and central looseness or cracks in the triangle zone and stress cracks.