The common element of stainless steel plate in more than 10, in addition to the basic elements of the iron and steel, properties and microstructure of stainless steel plate is the greatest impact elements including carbon, chromium, nickel, manganese, silicon, molybdenum, titanium, niobium, titanium, manganese, cobalt, copper, nitrogen etc.. When some elements coexist in the whole stainless steel, the influence of far is much more complex than when they exist independently, because not only to consider the elements of its function, but also pay attention to their effects caused by each other, so the performance of stainless steel is the sum of various elements affect the decision by the.
Chromium plays a decisive role in stainless steel. As long as it is stainless steel, it contains a certain amount of chromium. This is because the addition of chromium to the steel will lead to the movement of contradictions within the stainless steel to the benefit of resistance to corrosion damage. The main reason is to increase the electrode potential of Fe based solid solution. In addition, chromium also absorbs iron to make iron passivated.
Again, carbon is one of the major elements of industrial steel. The properties and organization of steel are largely determined by the content and distribution of carbon in steel, and the effect of carbon is more pronounced in stainless steel. Effect of carbon on microstructure in stainless steel is mainly manifested in two aspects, one is the stable austenite carbon element, and the effect extent is 30 times higher than the nickel effect, the second is because due to carbon and chromium and chromium affinity, forming a series of complex carbide. Therefore, from the two aspects of strength and corrosion resistance, the role of carbon in stainless steel is contradictory.
The role of nickel in stainless steel is to play with chromium to play out, nickel is an excellent corrosion resistant material, but also an important alloying elements alloying steel. Nickel in stainless steel is austenite formation elements, but the low carbon nickel steel to obtain pure austenite, nickel content must be as high as 24%. And only with nickel 27%, will make the stainless steel in some medium corrosion resistance has changed significantly. Therefore, nickel cannot be made into stainless steel separately. However, when nickel and chromium are present in stainless steel, nickel containing stainless steel has a lot of valuable properties. Nickel as alloying element in stainless steel, is the high chrome organization changes, so as to improve the corrosion resistance of stainless steel materials and process performance.
In addition of manganese and nitrogen can replace nickel chromium nickel stainless steel, chromium nickel austenitic stainless steel has the advantages of many, but over the years because refractoloy and heat resistant steel containing nickel below 20% a large number of development and application, and the chemical industry development needs more and more and the stainless steel, nickel deposits the relatively small and concentrated in a few areas in the world, so there is a contradiction in the supply and demand of nickel. Therefore in many other fields of stainless steel and alloy forging steel, tool steel, heat resistant steel etc., especially nickel less resources, widely carried out section of nickel and nickel with other elements of the generation of scientific research and production practice, the research in this aspect and is widely applied to manganese and nitrogen instead of nickel in stainless steel and heat resistant steel.
Manganese acts as an element of austenite, similar to nickel. More specifically, the role of manganese is not only lies in the formation of austenite, critical quenching speed can reduce the stainless steel, increase the stability of austenite during cooling, inhibit decomposition of austenite, the austenite under high temperature can be generated to maintain normal temperature. The corrosion resistance of stainless steel increased, little effect of manganese, nickel manganese austenite is about half the stability in the role of low nickel stainless steel, stainless steel and nickel free CrMnN Stainless steel has been used in the industry, some areas have been successfully used to replace 18-8 chromium nickel stainless steel.
Source: China Sheet Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)