渗氮处理（nitriding）.docVIP

渗氮处理（nitriding） Gas nitriding was developed and industrialized for the first time in 1923 by German Fry. As the products treated by this method have excellent wear resistance, fatigue resistance, corrosion resistance and high temperature resistance, the range of its application is gradually enlarged. For example, drills, screw taps, extrusion dies, die castings, press moulds, screws, links, crankshafts, suction and exhaust valves, gears, cams, etc. are all used. Brief introduction of nitriding steel The elements of aluminum, chromium, vanadium and molybdenum in traditional alloy steels are very helpful for nitriding. These elements in the nitriding temperature, and the tendency of the nitrogen atom in contact, have stable nitrides. Molybdenum, in particular, is used not only as a constituent of nitrides but also as a brittleness to reduce the nitriding temperature. The elements in other alloy steels, such as nickel, copper, silicon and manganese, have little aid in nitriding. In general, if the steel contains one or more nitrides to form the element, the effect is better after nitriding. Among them, aluminum is the strongest nitride element, containing 0.85 ~ 1.5% aluminum nitriding the best results. In chromium steel, if there is enough content, can get good results. However, no alloy containing carbon steel, because its nitrided layer is very brittle, easy to peel, not suitable for nitriding steel. Six commonly used nitriding steels are as follows: (1) low alloy steel containing aluminium element (standard nitrided steel) (2) chromium containing medium carbon low alloy steel SAE 4100430051006100860087009800 system. (3) hot work die steel (containing about 5% chromium), SAE, H11 (SKD, 61), H12, H13 (4) Ferritic and martensitic stainless steel SAE 400 (5) austenitic stainless steel SAE 300 series (6) precipitation hardened stainless steel 17 - 4PH, 17, 7PH, A, 286 and so on The standard nitrided steel containing aluminum has a very high hardness and a high wear resi