Why is stainless steel magnetic?
Many customers often think that the magnet adsorption of stainless steel, to verify its merits and authenticity, and do not smoke without magnetism, that is good, genuine; smokers are magnetic, is considered a fake fake. In fact, this is a very one-sided, not practical, and the wrong way to identify, I hope the following content for your help!
There are kinds of stainless steel at room temperature, the organizational structure can be divided into several categories: 1. austenitic: such as 304, 321, 316, 310; 2. martensite or ferrite, such as 430, 420, 410; austenitic is non-magnetic or weak magnetic properties, martensite or ferrite is magnetic. Usually used as a decorative stainless steel pipe,Most of the stainless steel plate is Austenitic 304 stainless steel material, is generally non-magnetic or weakly magnetic, but fluctuations in chemical composition caused by smelting or processing of different magnetic properties may also appear, but this can not be considered to be counterfeit or substandard, what is the reason? The above mentioned austenite is non-magnetic or weakly magnetic, and martensite or ferrite is magnetic, due to melting segregation or improper heat treatment, will cause a small amount of martensite Austenitic 304 stainless steel body or ferrite.
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 martensitic transformation, the greater the magnetic properties of steel. Like a lot of steel strips, the product is made up of 103 tubes, without obvious magnetic induction, producing 9.5 tubes. Due to the large deformation of the Ling bend, the magnetic sense is obvious, and the square tube produced by the utility model has larger deformation than the round tube, especially the folding part, the deformation is more intense, and the magnetism is more obvious. In order to completely eliminate the magnetic properties of the 304 steel caused by the above reasons, the stable austenite structure can be recovered by the solution treatment at high temperature so as to eliminate the magnetism. In particular, magnetic because it causes 304 stainless steel, and other materials such as stainless steel, carbon steel, magnetic 430 is not the same level, that is to say the magnetic steel 304 always showed a weak magnetic.
