Explanation

Also called nitriding. A thermo-chemical treatment process in which steel parts are put into a medium with a certain nitrogen activity for heating and insulation, so as to increase the nitrogen content in the surface layer of steel parts and form a nitrogen rich hardening layer. Gas nitriding method is often used. nitriding temperature is slightly lower than Ft-N eutectoid temperature, mostly at 480-590 ° C, nitriding time is tens of hours, and nitriding layer depth is a few millimeters. Since the same solubility of nitrogen in ferrite is very small, the nitriding layer is mainly nitride layer, and the hardness can reach HV950-1200. Before nitriding, steel parts generally need to undergo quenching and tempering treatment, and after nitriding, heat treatment is no longer required. Both ionitricling and soft nitriding are accelerated nitriding processes. In order to strengthen the nitriding hardening effect, nitriding steel should generally contain strong nitride forming elements such as molybdenum, aluminum, vanadium, chromium, etc.

Classification