基于脉冲漏磁理论的铁磁性材料斜裂纹检测

Angular crack detection of ferromagnetic material based on pulsed magnetic flux leakage

在广泛应用于各行各业的铁磁性材料中,由于应力和环境等因素的作用,裂纹是其最常见的缺陷之一,且多以不规则的形状(如斜裂纹)存在。为了分析斜裂纹的脉冲漏磁信号特点,建立了脉冲漏磁检测斜裂纹的有限元仿真模型,对比分析了斜裂纹与垂直裂纹的脉冲漏磁信号的差异,提取并研究了相关特征量与斜裂纹尺寸的关系。同时,利用脉冲漏磁检测系统对几种斜裂纹进行了实验,检测结果与仿真分析结果一致,验证了利用脉冲漏磁检测斜裂纹的可行性,为下一步对斜裂纹的定量检测提供了理论指导。

Ferromagnetic materials were widely used in various applications, in which crack is one of the most common defects caused by stress and environment factors. It usually has irregular shape such as the oblique crack. In this paper, pulsed magnetic flux leakage was used to detect the cracks. The finite element model was established to analyze the characteristics of pulse magnetic flux leakage signals of angular defect. Comparing the signal of angular defect with rectangular defect, some features were extracted to recognize the angular crack. Then several experiments were carried out which detect the angular cracks with the pulsed magnetic flux leakage inspection system. The experimental result were consistent with the simulation one. It verifies the feasibility of detection angular crack with pulsed magnetic flux leakage and provides a theoretical guidance for the quantitative detection of angular cracks in ferromagnetic materials.