This type of steel includes low, medium and high chromium content. Low chromium ferritic stainless steel contains about 11% to 14% chromium, such as China's 00Cr12, 0Cr13Al. American AISI400, 405, 406MF-2 (see table). This type of steel has good toughness, plasticity, cold deformation and weldability. Because steel contains a certain amount of chromium and aluminum, it has good oxidation resistance and rust resistance. 405 can be used as petroleum refining tower, tank lining, steam turbine blade, high temperature sulfur corrosion resistance device, etc. 400 is used as household and office appliances. 409 is used in automobile exhaust muffler system devices and cold and warm water pipes. Medium chromium ferritic stainless steel, the chromium content is 14% to 19%, such as China's 1Cr17, 1Cr17Mo. American AISI429, 430, 433, 434, 435, 436, 439. This type of steel has better rust resistance and corrosion resistance. Its work hardening coefficient is small (n≈2), and it has good deep drawing performance, but its ductility is poor. 430 is used as parts of building decoration, automobile decoration, kitchen equipment, gas burner and nitric acid industrial equipment. 434 is used for exterior decoration of cars and buildings. 439 is used as hoses for gas water heaters, coal and gas pipelines, etc. High-chromium ferritic stainless steel contains 19%-30% chromium, such as Cr18Si2, Cr25 in China and AISI442, 443, and 446 in the United States. This type of steel has good oxidation resistance. 442 is used continuously in the atmosphere, the upper limit temperature is 1035℃, and the highest temperature for continuous use is 980℃. 446 has better oxidation resistance.
