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NV PROCESS

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		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.

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