宽厚板厂钢板探伤合格率攻关实践

Practice on Qualification Rate of Flaw Detection of Wide & Heavy Plate Plant

以宽厚板厂钢板探伤不合为研究对象，采用扫描电镜等手段对缺陷试样进行分析，探讨了探伤不合的主要原因，分析认为硫化锰夹杂物、马氏体脆性组织和氢的析出综合作用导致钢板心部应力集中开裂。根据裂纹发生原因提出相应的工艺优化措施，通过增加探伤板真空处理比例、优化坯料堆冷工艺和钢板堆冷工艺，探伤合格率由88．16％提升至99％以上。

According to disqualification plate by ultrasonic flaw detection at Wide ＆ Heavy Plate Plant, the defect sam- ple was analyzed by means of scanning electron microscopy. The result showed that the manganese sulfide inclusions, martensite brittle organization and precipitation of hydrogen were the main reasons led to the stress concentration in the center of the plate. Some improving measures was put forward such as increasing vacuum processing proportion, optimizing slab stack cooling process and plate stack cooling. Qualification rate has been increased from 88.16% to above 99%.