Nitriding furnace equipment
Nitriding furnace equipment:
nitriding is a chemical heat treatment process in which nitrogen atoms are infiltrated into the surface layer of a workpiece in a certain medium at a certain temperature. Common liquid nitriding, gas nitriding, ion nitriding. The traditional gas nitriding is to put the workpiece into a sealed container, and to pass the flowing ammonia gas and heat it. After a long time of heat preservation, the ammonia gas is thermally decomposed to generate active nitrogen atoms, which are continuously adsorbed to the surface of the workpiece and diffused into the surface layer of the workpiece. , thereby changing the chemical composition and structure of the surface layer to obtain excellent surface properties.
On the one hand, the nitrogen infiltrated into the steel forms iron nitride with different nitrogen content from the surface and the iron, and on the other hand, it combines with the alloying elements in the steel to form various alloy nitrides, especially aluminum nitride and chromium nitride. These nitrides have high hardness, thermal stability and high dispersion, which results in high surface hardness, wear resistance, fatigue strength, seizure resistance, resistance to atmospheric and superheated steam in nitriding steel. Corrosion resistance, temper softening resistance, and reduced notch sensitivity. Compared with the carburizing process, the nitriding temperature is relatively low, so the distortion is small, but because the core hardness is lower, the infiltration layer is also shallower, generally only meets the requirements of wear resistance and fatigue resistance under light and medium loads, or Machine parts that are resistant to heat and corrosion, as well as a variety of cutting tools, cold work and hot work dies. There are many methods for nitriding, and gas nitriding and ion nitriding are commonly used. The initial gas nitriding was limited to steel containing chromium and aluminum and later expanded to other steel grades. Nitriding has developed rapidly from theory to process and is becoming more and more perfect. The applicable materials and workpieces are also expanding, becoming one of the important chemical heat treatment processes.