提离值对X80钢磁力信号的影响

Effect of lift-off on magnetic signal of X80 steel

金属磁力检测技术是一种对铁磁材料进行早期损伤检测的无损检测方法,在金属损伤的磁力检测中,提离值对金属磁力信号有显著的影响。为了深入研究这种影响的规律,获得高质量的信号特征以定量评估提离值与损伤处的磁力信号的关系,以X80管线钢为研究对象,通过自行搭建的磁力检测模拟系统,不断改变探头的提离值,研究磁力信号的变化规律。结果表明,磁力信号与提离高度成负相关,当提离高度达到一定值时,磁力信号不再发生变化,且接近地磁场的磁场强度;磁力信号的峰值位置没有随着提离高度发生显著变化。由此得出:金属磁力检测探头的提离值影响磁场强度的大小,但对应力集中区域的判断影响较小.

Metal magnetic testing technology is a kind of non-destructive testing method for early damage detection of ferromagnetic materials, and litt-off has a significant effect on magnetic signal in magnetic testing of metal damage. To further study the law of the effect and obtain high-quality signal characteristics to quantitatively evaluate the relationship between lift-off and magnetic signal at damage part, the paper takes X80 pipeline steel as research object to study change rule of magnetic signal through constantly change lift-off of probe on the basis of self-built magnetic testing simulation system. The results show that magnetic signal is negatively correlated with lift-off height, which remains the same and close to magnetic field strength of geomagnetic field when lift-off height reaches a certain value, and peak position of magnetic signal does not change obviously with litt-off height. Thus, it is concluded that lift-off of metal magnetic testing probe influences strength of magnetic field, but with little effect on determining stress concentration area.