中厚板探伤不合格原因分析与改善措施

Cause Analysis on Flaw Detection Disqualification of Medium Steel Plate and Improvement Measures

借助金相显微镜、测厚仪等设备,对低合金类中厚板探伤不合格缺陷位置进行系统分析,认为钢中气体氢在夹杂物缺陷处聚集,并且钢板缓冷工序异常,导致气体、应力释放不均匀,缺陷位置应力开裂,是造成探伤不合格的主要原因。针对此类缺陷,采用RH真空轻处理、改善钢板堆冷条件,能够有效提升低合金类产品探伤合格率至100%。

With the help of metallographic microscope,thickness gauge and other equipment,the unqualified defect position of low alloy medium plate is analyzed systematically.It is considered that the stress induced cracking at defective position due to uneven gas and stress relieving is caused by gaseous hydrogen aggregated at inclusions and abnormal slow cooling of steel plate,which is the main cause of the flaw detection disqualification.For such defect,the flaw detection qualification rate of low alloy products can be effectively increased to 100%by adopting light RH vacuum treatment and improving stack cooling conditions of steel plate.