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NV PROCESS
Characteristics Principle of Process
Comparison of Performance Performance and Capability
Comparison of Various Processes Typical Applications
Processing Procedure

Unsurpassed Hardness and Wider Application

Patent obtained major developed countries
The NV Nitriding Process is a high evolved gas nitriding treatment



What Is Nitriding Treatment Technology?

Nitriding is a process of diffusing nitrogen into the surface of steel and producing a thin but very hard layer to protect the metal. Nitriding treatment is a highly specialized metal surface treatment that enhances the abrasion resistance of sliding mechanical parts.Currently the following three typical processes are available.Each has its own advantages and disadvantages.

Common Nitriding Processes

Gas Nitriding Process

Using ammonia gas, the gas nitriding process is a low-cost and environmentally sound technology.However, the types of steels to which this process is applicable are limited.

Applicable to a wide variety of steels environmentally acceptable low cost

Salt Bath Nitriding Process

A cyanide compound is used.The salt bath nitriding process can nitride a wide variety of steels but because it uses cyanide chemicals, it may pose environmental problems.

Ion Nitriding Process

The ion nitriding process uses ionized nitrogen gas.The limitations of ion nitriding include long pre-treatment washing and setting times, low productivity, and high capital cost.

The NV Nitriding Process Is Our Own Development - A Breakthrough Mass-Production Nitriding Process that Resolves All the Shortcomings of Other Nitriding Processes.
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Comparison of Various Nitriding Processes

Applicable Steel Types Nitriding Performance Low-temperature Treatment Productivity Load on the Environment Costs
Hardness Depth Control of White Layer
Gas Nitriding

Carbon steel
Alloy steel


Significantly affected by surface properties


Nitriding capability is low and it is difficult to control the white layer


Difficult


 




Mass-producibility is good and internal production is possible
Salt Bath Nitriding

Carbon steel
Low and high alloy steels
Stainless steel
Cast iron


Significantly affected by shape and salt bath


Batch-by-batch adjustment is impossible


Possible to a certain extent


 




Mass-producibility is good but internal production is very difficult
Ion Nitriding

Carbon steel
Low and high alloy steels
Stainless steel
Cast iron


Significantly affected by shape of workpiece


Controllable to a certain extent


Possible


Low




Mass-producibility is not good
NV Nitriding

Carbon steel
Low and high alloy steels
Stainless steel
Cast iron
Nickel-based alloys


Not affected by either shape or properties of workpiece and highly stable


White layer is freely controllable by gas atmosphere control


Possible


 




Mass-producibility is good and internal production is possible

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Heating Pattern and Treatment Process

A newly developed gas activation treatment allows the nitriding temperature to be lowered down to the lowest possible level at which ammonia decomposes. The NV process allows the combination of temperature, time and gas composition to be freely controlled.



-The lower the nitriding temperature, the smaller the strain and the smoother the surface.
-Possible to set a wide range of nitriding temperatures from 400 to 600 degrees C.
-A low-temperature (NV-300) treatment allows nitriding at 300 degrees C due to an activation effect.

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Principle of NV Nitriding Process

The NV Nitriding Process is a totally new nitriding technology that combines the two treatment processes.

The NV Nitriding Process is a totally new nitriding technology that combines the two treatment processes.

The surface of most metals is covered with a fine oxide film. This oxide film protects against the intrusion of nitrogen atoms, so any metal surface treatment is significantly affected by the oxide film.

Gas Activation Treatment

NV gas eliminates the oxide film and replaces it with a fluoride film. Raising the processing temperature further activates the fluoride film.

Gas Nitriding

The introduction of ammonia gas instantly removes the fluoride film and allows nitrogen atoms to quickly diffuse deep into the surface of the metal.


OOxygen

FFluorine

NNitrogen


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