深圳市中科五金制品有限公司

       In daily life, there are a lot of stainless steel have a superficial knowledge of people through a non-magnetic stainless steel stainless steel to judge, is not magnetic, magnetic not is stainless steel, stainless iron. For example, we go to the supermarket to buy stainless steel goods, supermarket salesman will tell you the same recognition approach, even with a magnet, let your dear eyes try.

In fact, this is a misunderstanding of the concept is not clear because of the stainless steel produced by. From the point of view of metal perspective, "steel" and "iron" is merely the difference of carbon content, and the magnetic independent. In fact, according to the classification of common stainless steel microstructure characteristics, can be divided into austenitic stainless steel, martensitic stainless steel and ferritic stainless steel three class.

Austenitic stainless steel is the most widely used in factory of stainless steel, the chromium content of it is about 18%, and nickel content of about 8% belong to the chromium nickel stainless steel, the habit of Yi called type 18-8 stainless steel. The carbon content of it is low, due to nickel people, after a solid Fu after treatment at room temperature, the microstructure is austenite, is usually not magnetic. But the chemical composition fluctuation caused by smelting or processing status may also be different magnetic. Such as O304 stainless steel smelting, because when segregation or improper heat treatment, there will be a small amount of martensite or ferrite tissue iron. In this way, it will be with a weak magnetic. In addition, 304 stainless steel after cold working, can precipitate in martensite steel quantity, this steel will have a certain magnetism, and the greater the degree of cold deformation, the greater the magnetic properties of steel.

Martensitic stainless steel belongs to chromium stainless steel with high carbon content of it, after heat treatment, can significantly adjust the mechanical properties. Therefore, this kind of steel after quenching and tempering are generally required to use only. At room temperature, the microstructure of tempered martensite, with strong ferromagnetism, such as 1Cr13, 2Cr13, 3Cr13, 4Cr13, 7Cr13 etc..

Ferrite stainless steel also belongs to Hugh chromium stainless steel, the chromium content is generally greater than 11.5%, at room temperature, the microstructure of single-phase ferrite Hugh organization, even if the steel is heated from room temperature to high temperature (900~1100 DEG C). The occurrence of significant changes in the tissue is not. This kind of steel also has iron strong magnetic, on behalf of the brand has 430 etc..

From the above analysis we can see that, whether with ferromagnetism to determine the method of stainless steel material is not correct. First of all, as the most common austenitic stainless steel, such as 304, then it is possible, even if it is magnetic and martensitic or ferritic stainless steel, the corrosion resistance abilities may be slightly worse, but considering the price and the use of the environment, if used properly, is completely can be corrosion resistant, is completely stainless steel.