How to judge the quality and authenticity of 310s stainless steel plate

　　Many people often believe that magnets adsorb 310S stainless steel plates to verify their quality and authenticity. If they do not adsorb, there is no magnetism, and they believe it is good and genuine; Suction has magnetism, so it is considered a counterfeit or counterfeit. Originally, this was an extremely one-sided and erroneous method of distinguishing. In fact, 310S stainless steel plates can also "rust" and have magnetic properties. 310S stainless steel plates are made of high alloy steel with a matrix of over 60% iron and alloying elements such as chromium, nickel, and molybdenum. Their biggest characteristic is their strong corrosion resistance, but 310S stainless steel plates are not absolutely rust free. In coastal areas or some areas with severe air pollution, when the content of chloride ions in the air is high, there may be some rust spots on the surface of 310S stainless steel plates exposed to the atmosphere. However, these rust spots are limited to the surface and will not corrode the internal matrix of 310S stainless steel plates.

　　There are many varieties of 310S stainless steel plates, most of which are magnetic. Therefore, using magnets to adsorb is not a scientific method to distinguish 310S stainless steel plates. The 310S stainless steel plates commonly used for decorative tube sheets are mostly austenitic 304 materials, which are generally non magnetic or weakly magnetic. However, due to fluctuations in chemical composition or different processing conditions caused by smelting, magnetism may also occur. However, this cannot be considered as counterfeit or unqualified. What is the reason for this?

　　As mentioned above, austenite is non magnetic or weakly magnetic, while martensite or ferrite is magnetic. Due to component segregation or improper heat treatment during smelting, a small amount of martensite or ferrite structure can be found in austenitic 310S stainless steel plates. In this way, the 310S stainless steel plate will have weak magnetism.