Why does 304 stainless steel have some magnetism?

304 stainless steel belongs to austenitic type. The chemical composition of 304 stainless steel fluctuates through smelting, which makes 304 stainless steel contain a small amount of ferrite structure. That is why 304 stainless steel produces weak magnetism. This is why 304 stainless steel has magnetism.

In the process of cold working of 304 stainless steel, the structure of 304 stainless steel itself will also transform to ferrite. The greater the degree of deformation in the cold working process, the greater the transformation of ferrite structure, and the magnetic properties of 304 stainless steel will be The larger the deformation of the square and rectangular products produced by the cold working process is greater than that of the round shapes, so the magnetism of the production of square rectangles will be much more than that of the production of round shapes, especially the corners of the square rectangle, the magnetism is particularly obvious.

Of course, this kind of magnetism of 304 stainless steel can be completely removed by heat treatment. For example, the austenitic structure of 304 stainless steel can be restored by high temperature solution treatment, so as to eliminate the magnetism produced during cold working.

As an austenitic stainless steel, 304 stainless steel has relatively weak corrosion resistance, but the price and use environment of the stainless steel itself must be considered comprehensively. As long as it is used properly, it can fully resist corrosion and not easily damage. Stainless steel is generally divided according to the organizational structure, which can be divided into austenite, ferrite, martensite and other categories. The magnetism produced by 304 stainless steel is completely different from the magnetism produced by other materials of stainless steel. In general, the magnetism of 304 stainless steel always shows weak magnetism.

Summary: Non-magnetic austenitic 304 stainless steel transforms into magnetic martensite through the structural change formed by cold working. Therefore, 304 stainless steel is magnetic, but 304 stainless steel is weakly magnetic.