Metal Heat Treating —
Plasma Nitriding

Plasma nitriding is a unique heat treating process that diffuses nitrogen into the surface of a metal to create a case-hardened surface. These processes are most commonly used on low-carbon, low-alloy steels and medium and high-carbon steels, titanium, aluminum and molybdenum.

Magnum Metal Treating has two plasma nitride furnaces with maximum working dimensions of 48" wide by 72" long.

To begin this fairly new process, the customer parts are cleaned and stop-off points are applied to the area to be protected from the nitrogen. When the parts are loaded into the furnace and the pumps turned on, a vacuum is created.

The next stage is called "sputtering." A controlled amount of nitrogen and hydrogen is introduced into the furnace and an electric current is passed through the gas to the points creating a plasma on the surface. This high hydrogen plasma continues the cleaning process and is crucial for the effective nitriding of stainless steel and high nickel alloys by removing chromium oxides. Next, the nitrogen is increased and the diffusion process begins creating nitride compounds with the alloy elements in the steel.

The advantages of plasma nitriding parts are:

• Improved wear resistance
• Improved corrosion resistance in many alloys
• Improved resistance to galling in stainless steels