Magnetic stainless steel

People often assume that the adsorption of stainless steel magnet, and verify the authenticity of their advantages and disadvantages, do not smoke, non-magnetic, considered to be a good, genuine; suck those magnetic, is considered to be counterfeit fakes. In fact, this is an extremely one-sided, no practical method to identify errors. Many types of stainless steel screws, at room temperature, according to the organizational structure can be divided into several categories:
1. Austenitic type: If 304,321,316,310, etc;
2. Martensite or ferrite: as 430,420,410, etc.;
Austenitic type is non-magnetic or weakly magnetic, martensite or ferrite is magnetic.
Usually used as a decorative tube plate is austenitic stainless majority of 304, in general, is a non-magnetic or weakly magnetic, but the chemical composition fluctuations caused by smelting or processing may occur in different magnetic state, but can not be considered counterfeit or substandard, which is what causes it?
Austenitic mentioned above are non-magnetic or weakly magnetic, and martensite or ferrite is magnetic, due to improper segregation smelting or heat, can cause a small amount of martensite in austenitic 304 stainless steel or ferrite body tissue. Thus, the 304 will carry the weak magnetism.
Further, 304 stainless steel wire after cold working to the martensite transformation structure also, the greater the degree of cold deformation, more martensite transformation, the greater the magnetic steel. Like steel batch numbers, production Φ76 tube, no significant magnetic induction, production Φ9.5 tube. Ling bending deformation due to the larger number of magnetic induction is obvious, because the production of rectangular tube pipe deformation than large, especially knuckle part, more intense magnetic distortion is more evident.
To completely eliminate the magnetic steel above 304 causes, can be opened to restore stability austenite at high temperature solution treatment, thereby erasing magnetic.
In particular, proposed that the magnetic 304 stainless steel caused due to the above reasons, and other materials of stainless steel, such as 430, magnetic steel is absolutely not the same level, ie Stainless Steel Spring Wire always shows weak magnetism.
This tells us that if the weak magnetic stainless steel or entirely without magnetic, should be determined as 304 or 316; if the magnetic steel of the same, showing a ferromagnetic, because discrimination is not 304.