Stainless steel fasteners to choose the requirements of the main timber is stainless steel, stainless steel is not easy to rust the steel, in fact, part of the stainless steel, both stainless, and acid resistance (corrosion resistance). The stainless steel＇s stainless and corrosion resistance is due to the formation of chromium-rich oxide film (passivation film) on its surface. This kind of stainless steel and corrosion resistance is relative.
 
The results show that the corrosion resistance of steel in the weak medium such as atmosphere, water and nitric acid increases with the increase of chromium content in steel. When the chromium content reaches a certain percentage, the corrosion resistance of steel occurs Mutation, that is, from easy to rust to rust, never corrosion to corrosion.
There are many ways to classify stainless steel. According to the composition of the main chemical composition classification, basically can be divided into two kinds of chrome stainless steel and chrome-nickel stainless steel system; according to the use of points There are resistant nitric acid stainless steel, resistant to sulfuric acid stainless steel, resistant to seawater stainless steel standard parts, etc., according to the type of corrosion can be divided into pitting corrosion stainless steel, stress corrosion corrosion of stainless steel, corrosion resistance between the stainless steel, etc .; according to functional characteristics can be divided For non-magnetic stainless steel, easy cutting stainless steel, low temperature stainless steel, high strength stainless steel and so on.
 
Because stainless steel has excellent corrosion resistance, formability, compatibility and strength and toughness in a wide temperature range and other characteristics, so in the heavy industry, light industry, household goods industry and building decoration and other industries to obtain a wide range of applications The
 
Stainless steel fasteners one of the austenitic stainless steel
Stainless steel with austenitic structure at room temperature. Steel containing about 18% Cr, Ni 8% ~ 10%, C about 0.1%, with a stable austenite. Austenitic chrome-nickel stainless steel includes the famous 18Cr-8Ni steel and on this basis to increase the Cr, Ni content and adding Mo, Cu, Si, Nb, Ti and other elements developed high Cr-Ni series steel. Austenitic stainless steel is non-magnetic and has high toughness and plasticity, but the strength is low, it is impossible to strengthen by phase change, only through cold processing to strengthen. Such as adding S, Ca, Se, Te and other elements, it has a good machinability. Stainless steel standard parts Such steel in addition to oxidation of acid medium corrosion, if containing Mo, Cu and other elements can also be resistant to sulfuric acid, phosphoric acid and formic acid, acetic acid, urea and other corrosion. If the carbon content of such steel is less than 0.03% or Ti, Ni, it can significantly improve its resistance to intergranular corrosion. High silicon austenitic stainless steel concentrated nitric acid is willing to have good corrosion resistance. As the austenitic stainless steel has a comprehensive and good overall performance, in all walks of life to obtain a wide range of applications.
 
Stainless steel firmware with two ferrite stainless steel
In the use of state to ferritic organization mainly stainless steel. Chromium content of 11% to 30%, with a body-centered cubic crystal structure. This type of steel is generally free of nickel, and sometimes also contains a small amount of Mo, Ti, Nb and so on to the elements, such steel with large thermal conductivity, small expansion coefficient, good oxidation resistance, excellent resistance to stress corrosion, and more for the manufacture of atmospheric , Water vapor, water and oxidizing acid corrosion parts. This type of steel is poor in plasticity, after welding plasticity and corrosion resistance significantly reduced and other shortcomings, thus limiting its application. Furnace refining technology (AOD or VOD) applications can make carbon, nitrogen and other gap elements greatly reduced, stainless steel standard parts so that this type of steel is widely used.