304 why is stainless steel magnetic?
Some people often think that the inspection of stainless steel with good or bad, using a magnet, magnet does not smoke, no magnetic, genuine; smoke, then there is magnetism, is considered a fake fake. In fact, this is an extremely one-sided and unrealistic method of discrimination.Generally speaking, stainless steel has magnetism and also has no magnetism. The austenite is nonmagnetic or weakly magnetic, such as 201, 202, 304, 316, etc. the martensite or ferrite is magnetic, such as 430, 420, 410, etc..
304 stainless steel after cold processing, the structure of the structure will also change to martensite, and the greater the deformation degree of cold work, the more martensite transformation, the greater the magnetism. Like a lot of stainless steel wire, made straight, no obvious induction, but it is bent into a rectangular or circular, and produce some magnetic for cold bending deformation is large, especially the angle of magnetic is more obvious.In order to eliminate the magnetism of the 304 stainless steel, the austenite structure can be recovered by high temperature treatment so as to eliminate magnetism.Special remind is, 304 magnetic stainless steel because it causes, and other materials such as stainless steel, carbon steel, magnetic 430 is not the same level, that is to say the magnetic stainless steel 304 is always weakly magnetic.
However, due to segregation or improper heat treatment during smelting, there will be a small amount of martensite or ferrite in Austenitic 304 stainless steel. In this way, 304 stainless steel will have a weak magnetic.
