Because 304 stainless steel is cold processed, the structure will also be transformed to martensite, the greater the deformation of cold processing, the more martensite transformation, the greater the magnetism. After the cold heading cold rolling of stainless steel, their molecular arrangement will be changed to cause micromagnetism, but this is only physical, chemical properties are not changed.

In addition, like a batch of stainless steel wire, made into a straight branch, no obvious magnetic sensation, but when it is bent into a rectangle or circle, some magnetism is generated due to the large cold bending deformation, especially the magnetism of the corner part is more obvious. In order to complete the elimination of the magnetism of the 304 stainless steel, the stable austenite structure can be restored by high temperature treatment, so as to eliminate the magnetism.

Some people often think that the test stainless steel is good or bad with magnets, magnets do not attract, no magnetism, genuine; If it is magnetic, it is considered to be a fake. In fact, this is an extremely one-sided, impractical and wrong method of identification. 304 stainless steel is a common material in stainless steel, with a density of 7.93g/cm3, also known as 18/8 stainless steel in the industry. High temperature resistance of 800 degrees, with good processing performance, high toughness characteristics, widely used in industrial and furniture decoration industry and food and medical industry. 304 is a versatile stainless steel, which is widely used in the production of equipment and parts requiring good comprehensive properties (corrosion resistance and formability). In order to maintain the inherent corrosion resistance of stainless steel, the steel must contain more than 18% chromium and more than 8% nickel content. 304 stainless steel is a grade of stainless steel produced according to ASTM standards in the United States. Generally speaking, stainless steel has magnetic and non-magnetic. The Austenitic type is non-magnetic or weakly magnetic, such as 201, 202, 304, 316, etc. Martensite or ferrite is magnetic, such as 430, 420, 410, etc.

In particular, it should be reminded that the magnetism of 304 stainless steel caused by the above reasons is completely different from the magnetism of other materials, such as 430, carbon steel, etc., that is to say, the magnetism of 304 stainless steel is always weak magnetic. Simply put, if the stainless steel with weak magnetism or no magnetism at all, it should be judged as 304 or 316 material; If it is the same as the magnetism of carbon steel and shows strong magnetism, it is determined that it is not 304 material.