Q345E厚板在线探伤不合格的原因分析
Cause Analysis on Crack Detection of Unqualified Steel Plate
孟庆刚, 冯光宏, 于桂玲, 张江玲
点击：3511次 下载：0次
作者单位：(钢铁研究总院 冶金工艺研究所, 北京 100081)
中文关键字：中厚板； 在线超声探伤； 合格率
英文关键字：steel plate; ultrasonic inspection on line; qualification rate
中文摘要：从轧后出现的在线超声探伤不合格的钢板上取样，在缺陷处进行金相组织检验，并根据检验结果，利用裂纹扩展的基础理论进行分析，认为连铸坯的中心偏析是钢板在线探伤合格率偏低的根本原因，中心偏析的存在不仅有利于裂纹源硫化物的生成， 也会导致钢板中心出现脆硬的贝氏体和马氏体组织，为裂纹源的扩展提供条件，这些硫化物及其引发的裂纹促使氢原子的聚集和结合。这些缺陷综合在一起，最终降低了钢板在线探伤的合格率。
英文摘要：Sampling from the crack detection of unqualified steel plate, the microstructure of defects was tested. According to the metallographic result, theoretical analysis was carried on in order to find out the primary cause which led to the disqualification. The results show that the central segregation formed in the continuous casting process is the cause of low qualification rate. Central segregation is advantageous to sulfide creating, and the bainite and martensite appears, providing conditions for crack extending, which act as two necessary factors for the cracks and lead to the hydrogen aggregation. All these defects cause the low qualification rate of ultrasonic inspection on line for steel plate.