PLASMA NITRIDING SERVICES

Plasma heat treatment, especially PulsPlasma® nitriding and pulse plasma® nitrocarburizing is used for surface treatment of work pieces for protection against wear. For the treatment by plasma, the parts have to be placed in a vacuum chamber and are electrically insulated from the case. At a pressure of 100 - 1000 Pa, a pulsed electrical D.C. voltage of several hundred volts is used between work piece and chamber, whereby the workload is switched cathodically. The ionizing of the remaining gas in the chamber results in a glow discharge. The electrical, positive ions are moving towards the work piece and impact with high kinetic energy.

PLASMA NITRIDING TABS

4TON(1200 W X 1200 H X 1800 D)mm

Hot Wall Bell Type Furnace

Vacuum Chamber with Plasma View Port

3-Zone Heating 75KW, 2 main X 3 workload

Thermocouple for Regulation, Supervision & Recording

5 Gas Control Unit, Gas Mixture & Gas Regulation including
mass flow controllers(MFC).

Internal Fan for Regulation

Pulsed Technique by PLATEG

Auxiliary Heating & Thermal insulation

Gas Control Unit

Process Control & Regulation

Plasma Nitrocarburizing

Pre & Post Oxidation (PulsPlasma®)

Oxynitrocarburising

LPlasma Assisted Carbonitriding

Nitriding is the general name of some techniques that add nitrogen to a material to change some of its properties. In metallurgy, nitriding is used to improve physical properties, like hardness and wear resistance, and chemical properties, like corrosion resistance. Several approaches to perform this process have been developed like gas nitriding, plasma nitriding and salt bath Nitriding. Each one have its on particularities and is more suitable to one particular situation. These processes are applied to different sorts of materials like tool steels, stainless steels, aluminium alloys and others. For each material and each application, a particular nitriding process will lead to optimized service live for the work piece.

This research project was focused on AISI H13 tool steel nitrided by plasma nitriding processes. The nitriding was done either in a industrial plant or in a high precision scientific ion source. These two systems were useful to identify interesting aspects of the nitriding. In particular, the effect of different temperatures was investigated in detail. Another concept that was developed in this research is the formation of a steady-state in plasma nitriding when the surface has reached an balance between in flow of nitrogen from the plasma and the diffusion of nitrogen to the bulk. This effect is particularly important at low temperatures as those used for stainless steels or eventually tool steels.