Chromium 15% to 30%. Its corrosion resistance, toughness and weldability with the increase of chromium content increased resistance to chloride stress corrosion better than other types of stainless steel, fall into this category have Crl7, Cr17Mo2Ti, Cr25, Cr25Mo3Ti, Cr28 and so on.
Ferritic stainless steel because of high chromium content, corrosion and oxidation resistance are relatively good, but poor mechanical properties and process performance, and more for large discontinuity acid structure and antioxidant for steel. Such stainless steel is resistant to corrosive atmosphere, nitric acid and saline solution, and has good oxidation resistance, thermal expansion coefficient, etc., for the nitric acid plant equipment and food, can also be produced parts at high temperatures, such as gas turbine parts, etc. .