micro night

Micronite is a hardening treatment for stainless steel. Austenitic stainless steel (SUS304, 316L, etc.) has excellent corrosion resistance, but because it is soft, it is prone to wear, galling, and scratches. These problems can be improved by coating or nitriding to harden the surface.

Countermeasures and problems

Coating improves wear resistance by applying hard films such as TiN, CrN, and DLC, but the problem is that the gap between hardness and stainless steel is large. When a load is applied from the outside, the underlying stainless steel deforms, and the hard film that cannot follow the deformation peels off. On the other hand, with regard to nitriding of stainless steel, until now it was not possible to improve wear resistance without sacrificing corrosion resistance. Corrosion resistance is ensured by a Cr passivation film, but the nitriding treatment prevents the formation of a passivation film, resulting in poor corrosion resistance.

New technology micro night

Unlike the conventional nitriding treatment, Micronite developed by our company is a new nitriding treatment that achieves both corrosion resistance and wear resistance. Nitriding at a low temperature of less than 400°C suppresses the formation of Cr oxides in the nitrided layer (S phase), facilitating the formation of a passive Cr film. As a result, we succeeded in suppressing the deterioration of corrosion resistance. A salt spray test was conducted in comparison with conventional nitriding treatment, and superior results were obtained. The surface hardness is more than doubled due to the formation of the nitride layer. The gap between the underlying stainless steel and the hardness of the outermost surface is narrower than with a coating. Therefore, the outermost surface can easily follow even if it receives an external load. Furthermore, by combining our micro dimple treatment (MD treatment), the surface hardness increases to about 5 times due to work hardening due to the peening effect.

Scope of application

・Abrasion and rust prevention measures for transportation equipment parts for packaging films and plastic containers for food, pharmaceuticals, cosmetics, etc.
・Guides, sailors, end cutters, heater bars