The aluminum, chromium, vanadium and molybdenum elements in traditional alloy steel materials are very helpful for nitriding. When these elements come into contact with nascent nitrogen atoms at the nitriding temperature, stable nitrides are formed. In particular, the molybdenum element not only acts as an element for forming nitrides, but also acts as a reduction in brittleness that occurs at the nitriding temperature. The elements in other alloy steels, such as nickel, copper, silicon, manganese, etc., do not contribute much to the nitriding characteristics.
Generally speaking, if the steel contains one or more nitride-forming elements, the effect after nitriding is relatively good. Among them, aluminum is a strong nitride element, containing 0.85~1.5% aluminum as a result of nitriding. As far as chromium-containing chromium steel is concerned, if there is enough content, good results can also be obtained. However, there is no carbon steel containing alloy, because the nitrided layer is very brittle and easy to peel off, so it is not suitable for nitriding steel.