Nitriding (NITAI®)

Nitriding/Nitrocarburising

All the nitriding and nitrocarburising processes of the HAUCK Group share the designation NITAI® . Nitriding and nitrocarburising improve the mechanical properties of component surface layers. In nitriding, workpieces are exposed to a nitrogen releasing environment at a temperature from 450 to 550 °C, so that nitrogen diffuses out of the nitriding agent into the surface of the workpieces. In the case of nitrocarburising, which takes place from 550 to 580 °C, additional media releasing carbon are added, so that carbon, as well as nitrogen, diffuses into the surface of the workpieces. All steel, cast iron and sinter materials in general use can be treated. Both unalloyed and low and medium alloyed steels are suitable. High alloy steels with more than 13 % chromium are only suitable with reservations because of their surface passivity. Alloying elements such as aluminium, vanadium, chromium and titanium enhance the hardness increase in the surface layer.

Improved properties

  • High wear resistance in the case of adhesion
  • Reduction of coefficients of friction
  • Increased corrosion resistance
  • Improvement of heat resistance up to approx. 500 °C
  • High abrasion resistance
  • Good dimensional stability and shape retention
  • Attractive surface appearance
  • Improvement of fatigue strength

Areas of application

  • General mechanical engineering
  • Valve construction
  • Automobile manufacture
  • Fastening technology
  • Mining
  • Press manufacturing industry
  • Rail technology
  • Electronics/Electrical engineering
  • Energy and reactor technology
  • Aircraft construction
  • Household appliance industry
  • Hydraulics and
  • pneumatics industries
  • Medical technology
  • Instrumentation and control technology
  • Textile industry
  • Defence technology
  • Toolmaking

Variants

Gas nitriding

In gas nitriding, the workpiece is treated in a stream of ammonia gas between 480 and 550 °C. Gas nitriding is only applied, as a rule, for alloyed steels.

Plasma nitriding

Plasma nitriding usually takes place at temperatures from 450 to 550 °C in a vacuum with the help of the plasma generated by a glow discharge on the workpiece surface.

Special process engineering features include mechanical insulators (covers).

Gas and plasma nitrocarburising process

The gas and plasma nitrocarburising process takes place best at a temperature of 550 to 580 °C in a nitrogen releasing gas mixture. Through the addition of carbon, the normal treatment times are shortened in relation to the pure nitriding process.