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Characteristics Principle of Process
Performance and Capability Typical Applications

Adding high durability to the beauty of stainless steel

Patent obtained in major developed countries
NV Pionite Treatment is Air Water's own technology used to harden the surface of austenitic stainless steel.

Characteristics of NP Pionite Treatment

NP Pionite Treatment is our own unique technology, capable of hardening the surface of austenitic stainless steels such as SUS 316[AISI type 316] while maintaining resistance to corrosion. Using activation treatment technology, a carbon solid-solution diffusion treatment maintains a tough and beautiful stainless steel surface. This NV Pionite Treatment is now in widespread use in various fields, including industrial products and household-related products.

10)	Cross Section Hardness Distribution Diffusion Layer
An austenitic stainless steel texture has a stable hardened layer

Principle of NV Pionite Treatment

Activation Treatment Technology Allows Carbon Solid-Solution Diffusion Treatment

NV Pionite Treatment is our own surface treatment technique that diffuses carbon in solid solution into the austenitic stainless steel texture at temperatures lower than 500 degrees C. Allowing carbon to diffuse completely into the spaces between crystals produces a surface that is hard and corrosion-resistant. The hardened layer itself characteristically forms a stable austenitic stainless steel texture.
Pionite Treatment = Gas Activation Treatment + Low-temperature Carbon Solid-solution

Austenitic Stainless Steels

(SUS 316[AISI type 316])

The surface of the stainless steel is covered with a passive film, which has a significant effect on surface treatment.

Gas Activation Treatment

NV gas eliminates the passive film and replaces it with a fluoride film.

Carbon Solid-solution Diffusion Treatment

A highly corrosion-resistant carbon solid-solution layer is formed. The austenitic stainless steel texture has a hardened layer that is stable.





Performance and Capability of NV Pionite Treatment

High surface hardness can be obtained and wear resistance and fatigue strength improved significantly.
NV Pionite Treatment extends the life of parts and maintains the beauty of materials.
NV Pionite Treatment can produce a hardened layer that is 50 to 60 times as wear resistant as hard chromium plated materials, and that has wear resistance equivalent to or greater than nitrided materials. The durability of products can be improved dramatically as a result.
Ohgoshi Method Wear Test
SUS 316
[AISI type 316] plate
Companion material:
SUJ2[AISI type 52100]
carburized and quenched material
Diameter 30 x 3.2 mm
Wear condition:
0.94 m/sec, 400 m
A supple hardened layer of the austenitic stainless steel texture significantly enhances fatigue strength, thereby extending the life of thin-walled, small-bore parts and allowing greater freedom of design.
Fatigue Strength Test (S-N Curve)
SUS 316
[AISI type 316]
NV Pionite Treatment delivers a steady torque coefficient and is effective in preventing the seizure of bolts and other clamping parts.
Bolt Seizure Test
Hexagon bolt M8
Axial force:
100 MPa
Tightening frequency:
10 times
Unlubricated and dry

The technology maintains the corrosion resistance and pitting corrosion resistance of austenitic stainless steels.
It is extensively used in corrosive environments.
NV Pionite Treatment provides outstanding resistance to acids and alkalis. It can be used for a wide variety of applications in corrosive environments that would normally pose problems for other materials.
Acid Resistance Test
(50 degrees C,6Hr)

(50 degrees C,6Hr)

The Pionite-treated hardened layer, unlike plated or nitrided layers, won't crack or peel off when bent.
This characteristic confers a tremendous advantage in plastic processing, such as when bending and pressing.

One of the properties of austenitic stainless steels is that it is nonmagnetic and this quality can be maintained with our process. The process displays its advantages in the surface treatment of precision parts and electric components that are sensitive to magnetic materials.
Maximum Surface Magnetic Flux Density