Ferritic stainless steel
Its internal microstructure of ferrite, the mass fraction of chromium in the range of 11.5% ~ 32.0%. With the increase of chromium content, its acid resistance also increased, after the addition of molybdenum (Mo), you can improve acid corrosion resistance and stress corrosion resistance. Such a national standard stainless steel grades 00Cr12, 1Cr17, 00Cr17Mo, 00Cr30Mo2 and so on.
430 is ferritic stainless steel
Ferritic stainless steels are low carbon chromium stainless steels containing more than 14% chromium, chromium stainless steels containing more than 27% chromium, and molybdenum, titanium, niobium, silicon, aluminum, Tungsten, vanadium and other elements of stainless steel, the chemical composition of the elements forming ferrite absolute advantage, the matrix is ferrite. This type of steel in the quenched (solid solution) state of the organization of ferrite, annealed and aging state of the organization can see a small amount of carbides and intermetallic compounds.
Belongs to this category are Crl7, Cr17Mo2Ti, Cr25, Cr25Mo3Ti, Cr28 and so on. Ferritic stainless steel because of high chromium content, corrosion resistance and oxidation resistance are better, but the mechanical properties and process performance is poor, mostly used in less resistant acid structure and as anti-oxidation steel.
Martensitic stainless steel
Its microstructure is martensite. The chromium content of this type of steel is 11.5% ~ 18.0%, but the carbon content of up to 0.6%. Increasing the carbon content increases the strength and hardness of the steel. A small amount of nickel added to this type of steel can promote the formation of martensite and at the same time increase its corrosion resistance. The weldability of this type of steel is poor. Included in the national standard plate steel 1Cr13, 2 Cr13, 3Cr13, 1Cr17Ni2 and so on.
410 is a martensitic stainless steel with a maximum carbon content of 0.15%, a maximum manganese content of 1.00%, a maximum silicon content of 1.00% and a chromium content of 11.50 to 13.50%. Universal heat-treatable stainless steel, corrosion-resistant, heat-resistant, hardness up to 42HRC or higher.
Austenitic stainless steel
Its microstructure is austenitic. It is in the high-chromium stainless steel to add the appropriate nickel (nickel mass fraction of 8% to 25%) formed by the austenitic stainless steel. Austenitic stainless steels are based on Cr18Ni19 iron-based alloys. Based on this, austenitic stainless steels develop into the series of chrome-nickel austenitic stainless steels shown in Fig. 1-2 with different uses.