It inherits the characteristics of high strength, good oxidation resistance and excellent stress corrosion resistance of ordinary ferritic stainless steel, and improves the ductility of brittle-brittle transition, sensitivity to intergranular corrosion and low toughness of welded state. Refining technology, reducing C and N content, adding stabilizing and weld metal toughening elements, can obtain high Cr, Mo and ultra-low C, N super ferritic stainless steel, making ferritic stainless steel corrosion-resistant, resistant Applications such as pitting and crevice corrosion of chlorides have entered a new phase.