The Introduction of Martensitic Stainless Steel
Standard martensitic stainless steels are: 403, 410, 414, 416, 416 (Se), 420, 430, 431, 440A, 440B and 440C, which are magnetic; the corrosion resistance of these steels comes from "chromium", the scope of which From 11.5 to 18%, the higher the chromium content, the higher the carbon content of the steel to ensure the formation of martensite during heat treatment. The above three types of 440 stainless steel are rarely considered as applications requiring welding, and the filler metal; 440 of the composition is not easy to obtain.
The improvement of standard martensitic steels, containing additives such as nickel, molybdenum, vanadium, etc.,which is mainly used to increase the allowable working temperature of standard steels to above 1100K. When these elements are added, the carbon content also increases. As the carbon content increases, the problem of avoiding cracks in the hardened heat affected zone of the weld becomes more serious.