用磁粉探伤方法检查出来的缺陷是多种多样的,例如:裂纹、发纹、白点、夹杂物、疏松、折叠、锻造分层、结疤等。产生缺陷的主要原因是浇铸工艺不稳定或锻造、轧制、冷加工、淬火、磨削等工艺不当所引起的。在缺陷处磁粉堆聚成不同的图象,我们凭借这些图象,可识别缺陷的性质,判断它们的形成原因,确定其危害程度。磁粉探伤中的某些缺陷,如白点、过烧后的晶界氧化物、发纹、熔合后的金属性异物、导磁率较强的金属夹杂物等等,单凭磁粉探伤是难以识别的,必须凭借超声波探伤,金相检验(宏观、微观)等试验配合,再了解一些材料性能(包括导磁性能),热锻,轧制,热处理,磨削等所造成的缺陷图象概念,从而达到正 Flaw detection using magnetic particle inspection methods are varied, such as: cracks, hair lines, white spots, inclusions, loose, folding, forging stratification, scarring and so on. The main reason for the defects caused by instability casting process or forging, rolling, cold, quenching, grinding and other improper process caused. In the defects of magnetic particles stacked into different images, we rely on these images, we can identify the nature of defects, determine their causes, to determine the extent of their harm. Magnetic flaw detection in some of the defects, such as white spots, overgrown grain boundary oxides, hair lines, after the fusion of metallic foreign bodies, magnetic permeability strong metal inclusions, etc., alone magnetic particle inspection is difficult to identify , We must understand the defect image concept caused by some material properties (including permeability), hot forging, rolling, heat treatment and grinding by means of ultrasonic flaw detection and metallographic examination (macro and micro) Achieve positive