1Cr15Ni4Mo3N沉淀硬化不锈钢磁粉检测疑似裂纹原因分析

1Cr15Ni4Mo3N沉淀硬化不锈钢螺栓零件在制造工序磁粉检测时,发现螺栓表面有一条疑似裂纹状线性磁痕显示,后采用荧光渗透检测方法进行辅助检测,原磁痕显示处未见异常荧光显示。结合金相试验分析发现,螺栓原材料内呈带状分布的残余奥氏体,破坏了基体组织和材料磁性的连续性导致出现磁痕显示。研究为该材料在零件制造中磁粉检测的磁痕判定提供了依据。

Analysis of Suspected Crack of 1 Cr15 Ni4 Mo3 N Precipitation-hardening Stainless Steel by Magnetic Particle Testing

A bolt of 1Cr15Ni4Mo3N precipitation-hardening stainless steel was found to have a suspected crack during magnetic particle testing. However, the bolt wasn＆#39;t found to have crack during the subsequent fluorescent testing. Metallographic examination was carried out. There were ribbon residual austenites in the matrix of the bolt, which destroyed the continuity of the microstructure and magnetic property, and thus resulted in magnetic mark display. The conclusion laid a foundation for magnetic mark judgment during magnetic particle testing in the manufacture process.