1. The main component of stainless steel is Cr (chromium). Only when the Cr content reaches a certain value, the steel has corrosion resistance. Therefore, stainless steel generally has a Cr (chromium) content of at least 10.5%.
2. Stainless steel also contains Ni, TiI, Mn, N, Nb, Mo, Si, Cu and other elements. The corrosion resistance of stainless steel decreases with the increase of carbon content. Therefore, the carbon content of most stainless steel is low, with a maximum of no more than 1.2%. The wc (carbon content) of some steels is even lower than 0.03% (00Cr12 ).
3. Chromium is the most important alloying element in austenitic stainless steel. The stainlessness and corrosion resistance of austenitic stainless steel are mainly obtained by chromium promoting the passivation of steel and keeping the steel stable under the action of contaminants. Passive results.
4. In austenitic stainless steel, chromium is an element that strongly forms and stabilizes iron, shrinking the austenite area. As the content in the steel increases, ferrite (6) structure may appear in austenitic stainless steel.
5. Research shows that in chromium-nickel austenitic stainless steel, when the carbon content is 0.1% and the chromium content is 18%, in order to obtain a stable single austenitic structure, the minimum nickel content is required, which is about 8%. From this point of view, the commonly used 18Cr-8Ni type chromium-nickel austenitic stainless steel is the most suitable one containing chromium and nickel.
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