X70管线钢金属磁记忆信号特征研究

The study of the metal magnetic memory signal’s feature in X70 pipe line steel

针对铁磁构件表面磁记忆信号法向分量在裂纹或应力集中处存在过零点现象,很多学者对此有争议,通过线切割模拟裂纹,在拉伸试验机上拉伸管道构件,并分析管道构件表面漏磁信号法向分量,发现在裂纹处法向分量确实存在过零点现象,但是过零点随着拉伸载荷的变化发生漂移,当载荷增加到一定程度过零点不再漂移。结果表明,不能单纯以法向分量过零点判断裂纹或应力集中处。

For that the normal component of metal member’s magnetic memory signal have zero where there is crack or focal point of sress that is in dispute for many scholars,the author simulate cracks by line cutting and draw pipeline component on pull test machine,and then analyze surfacial leaking magnetic signal’s normal component of pipeline component,by which discover there is really phenomena of crossing zero on crack,but crossing zero point occur drift by drawing load,and don’t drift when load increase to a certain degree.As a result,we can’t diagnose crack or focal point of stress simplely by normal component passing zero point.