Why stainless steel can be magnetic?

Some people think that iron absorption can distinguish between stainless steel and stainless steel. People often magnet adsorption stainless steel belt, verify its merits and authenticity, a suck non-magnetic, that is good, the real thing; sucked magnetic, it is considered to be a fake fake. In fact, this is an extremely one-sided, not practical and wrong identification method. 

What is stainless steel? In the field of materials science, the Cr content is greater than 10.5%, and corrosion resistance and stainless steel as the main performance of a series of iron-based alloys called stainless steel. Usually in the atmosphere, water vapor and fresh water, etc. less corrosive medium of stainless steel and corrosion-resistant steel is called stainless steel, in the acid and alkali salts and other corrosive environments with corrosion-resistant steel is called acid-resistant steel.

Why stainless steel can be magnetic?

There are many kinds of stainless steel, which can be divided into several categories according to the organizational structure at room temperature: 1. austenitic type: such as 304, 321, 316, 310, etc.; 2. martensitic or ferrite type: such as 430, 420, 410 and so on;
Austenitic type is non-magnetic stainless steel or weakly magnetic stainless steel, martensite or ferrite is magnetic. Due to the smelting of compositional segregation or improper heat treatment, it will cause a small amount of martensite or ferrite organization in the austenitic 304 stainless steel strip.

In this way, 304 stainless steel strip will have a weak magnetism in it. In addition, 304 stainless steel strip 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. To completely eliminate the magnetic properties of 304 steel caused by the above reasons, high temperature solution treatment can be used to restore the stable austenitic organization, thus eliminating the magnetic properties.

Post time: May-17-2024