It combines the high strength of carburizing treatment and the low strain characteristics of gas soft nitriding treatment, which is a new nitriding treatment technology. Morphology control of the iron-nitrogen compound layer is achieved by high-precision atmosphere control. Particularly excellent in pitting corrosion resistance and bending fatigue strength.

In the entire manufacturing process of nitriding parts, nitriding is often the last process, at most fine grinding or grinding. The process flow of nitriding parts is generally: forging → normalizing (annealing) → rough machining → quenching and tempering → finishing → stress relief → rough grinding → nitriding → fine grinding → assembly.

The preheating treatment before nitriding includes normalizing (annealing), quenching and tempering treatment, and stress relief.

a. Normalizing (annealing), the purpose of which is to refine grains, reduce hardness, and eliminate forging stress.

b. Quenching and tempering treatment can improve the processing performance of the steel and obtain a uniform tempered sorbite structure to ensure that the core of the part has sufficient strength and toughness, and at the same time, it can make the nitrided layer and the basic bond firmly.

c. Stress relief treatment, for precision parts with complex shapes, stress relief should be carried out 1~2 times before nitriding to reduce the deformation during nitriding.