People often think that the magnet adsorbs stainless steel material, to verify its merits and authenticity, does not suck no magnetic, that is good, the real thing; suckers have magnetic, it is considered counterfeit counterfeit. In fact, this is an extremely one-sided, not practical and wrong identification method.

There are a wide variety of stainless steel, at room temperature, according to the organizational structure can be divided into several categories: 1:

1 austenitic: such as 304, 321, 316, 310, etc;

2. martensitic or ferritic type: such as 430, 420, 410, etc;

      Austenitic type is non-magnetic or weakly magnetic, martensitic or ferritic is magnetic.

      Usually used as decorative pipe plate of stainless steel is mostly austenitic type 304 material, generally speaking is non-magnetic or weakly magnetic, but due to smelting caused by fluctuations in chemical composition or processing state may also appear magnetic, but this can not be considered impostor or substandard, what is the reason?

      Above mentioned austenite is non-magnetic or weakly magnetic, while martensite or ferrite is magnetic, due to smelting composition deviations or improper heat treatment, will cause a small amount of austenitic 304 stainless steel in martensite or ferrite organization. In this way, 304 stainless steel with a weak magnetic properties.

      In addition, 304 stainless steel after cold working, the organizational structure will also be transformed to martensite, the greater the degree of cold working deformation, the more martensite transformation, the greater the magnetic properties of steel. For example, the same batch number of steel strip, production Φ76 tube, no obvious magnetic sense, production Φ9.5 tube. Due to the larger deformation of cold bending, the magnetic sense is obvious, and the production of square rectangular pipe is more intense than round pipe because of the deformation, especially the corner part, the magnetic sense is more obvious.

      To completely eliminate the above-mentioned reasons for the magnetic properties of 304 steel, high-temperature solution treatment can be opened to restore stable austenite organization, thereby eliminating the magnetic properties.

      In particular, the above reasons for the magnetic properties of 304 stainless steel, and other materials of stainless steel, such as 430, carbon steel is not at all the same level of magnetism, that is, the magnetic properties of 304 steel always shows a weak magnetic properties.

      This tells us that if the stainless steel with weak magnetism or completely without magnetism, should be judged as 304 or 316 material; if the same as the carbon steel magnetism, showing strong magnetism, because the judgment is not 304 material.

      We recommend that the purchase of stainless steel products should be selected from reputable manufacturers, do not be greedy for cheap, beware of being fooled.