In the state of ordinary sheet or rolled sheet, without deep processing, it will not be attracted by the magnet, but if after deep drawing, the 304 is partially transformed into a martensitic structure, showing tiny magnetism, and it may be attracted to the magnet at this time. live. Therefore, if the plate can be attracted by the magnet, it must not be 304. If the product can be attracted by the magnet, it must not be demagnetized. Magnetite can absorb iron and nickel. If a stainless steel product can be absorbed, it means that it contains high iron and nickel content.
The general corrosion resistance of such stainless steel products is not very good, because the stainless properties of stainless steel are mainly derived from chromium metal. But it is cheaper and more durable. However, the quality of stainless steel cannot be identified only by magnets. Some inferior stainless steel products are mixed with a large amount of manganese metal. Manganese cannot be absorbed by magnets, but after adding manganese, the rust and corrosion resistance of the product is greatly reduced. Although such products cannot be absorbed by magnets, they are of poor quality.
There are two solid structures of iron, one is face-centered cubic, called austenite, and the other is body-centered cubic, called ferrite. Ordinary steel is ferrite at room temperature and can be absorbed by magnets. There are many kinds of stainless steel. The most common one is austenitic stainless steel containing chromium and nickel, such as 0Cr18Ni9, which contains 18% chromium and 9% nickel. This stainless steel has very weak magnetic properties.
The chromium-containing stainless steels that do not contain nickel or have low nickel are generally martensitic stainless steels, such as Cr12, which are magnetic, and their corrosion resistance is not as good as austenitic stainless steels. In recent years, due to the soaring price of nickel, some unscrupulous manufacturers have been asked to replace austenitic stainless steel with martensitic stainless steel. Therefore, you can bring a NdFeB magnet to check stainless steel. Good stainless steel.