There are more than 10 kinds of common elements in stainless steel plate. In addition to the basic element iron, the most important elements affecting the performance and microstructure of stainless steel plates are carbon, chromium, nickel, manganese, silicon, molybdenum, titanium, niobium, titanium, manganese, nitrogen, copper, cobalt and so on. 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 the stainless steel contains a certain amount of chromium. This is because the addition of chromium to the steel will result in the movement of stainless steel inside the contradiction to the resistance to corrosion damage. The main reason is to increase the electrode potential of Fe based solid solution, in addition, chromium also absorbs the iron electron to make iron passivation.
In addition, carbon is one of the main elements of industrial steel. The properties and structure of steel are largely determined by the content and distribution of carbon in steel, and the effect of carbon in stainless steel is more obvious. The effect of carbon on the microstructure of stainless steel is mainly manifested in two aspects, one of which is stable austenite elements, and the degree of action is great, is 30 times the effect of nickel, and the other is because of the great affinity of carbon and chromium, and chromium formation of a series of complex carbide. Therefore, from the two aspects of strength and corrosion resistance candle, 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 of alloy 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%. Only when the content of nickel is 27%, can the corrosion resistance of stainless steel change obviously in some media. Therefore, nickel can not be made into stainless steel alone. However, nickel and chromium exist in stainless steel at the same time, 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.
The effect of manganese on austenite is similar to that of nickel. More precisely, the effect of manganese is not on the formation of austenite, but because it can reduce the critical quenching rate of stainless steel, increase the stability of austenite in cooling, inhibit the decomposition of austenite, so that the austenitic structure at high temperature can be maintained at room 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 Stainless Steel Plate Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)