Well nitriding furnace is a surface nitriding furnace. Surface nitriding makes the surface have a certain hardness. Nitriding furnace chemical heat treatment: refers to the heat treatment process in which metal or alloy workpieces are placed in an active medium at a certain temperature for heat preservation, so that one or more elements penetrate into its surface layer to change its chemical composition, structure and properties. The box type multipurpose furnace is mainly used for gas carburizing direct quenching of workpieces, gas carburizing quenching with intermediate cooling, gas carburizing protective gas cooling, re carburizing, carbonitriding and quenching, nitrocarburizing (soft nitriding), isothermal quenching, bright normalizing, bright annealing, brazing and sintering. Multipurpose furnace is a continuous production thermal equipment with multi-layer hearth, also known as rake furnace or multi chamber furnace. It is used for burning municipal waste, roasting nonferrous metal ore powder, lightly burning magnesium hydroxide filter cake and natural magnesite ore powder. Nitriding furnace is also called diffusion nitriding. Nitriding furnace has the following five advantages:
① high hardness and high wear resistance
hardness analysis of nitrided steel parts such as 38CrMoAlA can be developed to hv1000 ~ 1200, equivalent to about HRC70. This is obviously what we can't achieve by quenching or carburizing quenching technology. Especially important and valuable is that this kind of high hardness can keep the long-term economic growth of the enterprise at about 500 ℃. Due to the high hardness and good wear resistance, it can resist the wear of various data types
② high fatigue strength
after nitriding, the specific volume of various nitride phases formed on the surface of parts is greater than the specific volume of iron, so there is a large residual compressive stress on the surface after nitriding
③ high anti bite performance
some high-speed relative sliding parts are easy to get stuck or scratched when they lack lubrication or overheat in a short time, while nitrided parts can maintain high hardness and high anti bite performance
④ high corrosion resistance
after nitriding, a dense nitride layer with high chemical stability is formed on the surface of the parts, which significantly improves the corrosion resistance and can resist the corrosion of atmosphere, tap water, steam, benzene, oil stain and weak reducing solution, so as to maintain good corrosion resistance
⑤ small and regular deformation
because the nitriding temperature is low, generally 480 ~ 580 ℃, the temperature rise and fall processing speed is very slow, and there is no management organization structure change in the heart of the part, The structure still maintains the quenched and tempered state, so the influence of Nitriding on the deformation of part materials is very small, and we can learn and control the law of this deformation
before nitriding, the product surface is activated by nano gas (H2S), and sulfide diffuses to the product surface during nitriding. By forming sulfide (steel) on the top surface of the product, the initial service performance and friction performance (through solid lubrication) are improved. Controlled by computer, the structure and hardness are uniform, and the repeatability of nitriding layer is good
gas sulfur impregnation nitriding is characterized by gas sulfur impregnation nitriding with N2, NH3 and nm gas as raw materials; Nitriding temperature 400 ~ 620 ℃; The treatment time is 3-5 hours. Gas impregnation nitriding has good wear resistance, flame resistance, bite resistance, fatigue strength, corrosion resistance and vibration resistance
