For hardening of steel surfaces different methods can be used.
Carburizing is a hardening process for low-carbon steels.
Carbon diffuses into the steel surface and after quenching forms martensite.
In gas carburizing, the commercially most important form of carburizing, the carbon source is a carbon-rich gas containing carbon monoxide CO. It is produced either from gaseous hydrocarbons such as methane, propane, and butane, or by vaporizing and cracking heavier hydrocarbons.
Carbonitriding is a variation of gas carburizing and is somewhat closer to carburizing than to pure nitriding.
In this case ammonia is introduced into the furnace as an additional nitrogen source. Nitrogen is formed at the metal surface by ammonia dissociation and diffuses together with carbon into the steel. The temperature is lower compared to carburizing.
Nitriding is a surface hardening method that uses ammonia as the process gas to introduce nitrogen into the iron lattice at relatively low temperatures. In this case the steel does not need to be quenched.
Continuous carburizing furnace (tray pusher type, roller transport furnace)
Consistent product properties are ensured by the cylindrical construction and excellent insulation. The furnace offers good temperature uniformity and variable gas control coupled with a state-of-the-art configuration and production management system.
- ● Gas quenching can optionally be integrated into the furnace to achieve a low quenching strain, minimal distortion and uniform hardness distribution.
- ● An atmosphere rich in carbon monoxide CO enables a reduction of the process time for carburizing.
Continuous rotary drum furnace for carburizing
This type of equipment is most useful for a process involving small parts-supplying, carburized hardening, washing, tempering and removal are carried out continously in a completely integrated heat treating system.
Top-load pit furnace
This is a muffle furnace using Moldatherm® heating elements. Characteristic features of this furnace type are rapid temperature stabilization, excellent heating/cooling properties, easy maintenance and energy saving operation.
KCF carburizing furnace
The KCF carburizing furnace is flexible and can accommodate a wide variety of products. Due to good insulation and the resulting low heat loss it can be operated energy-efficiently. Pressure and temperature can be kept very stable.
Flameless KCF carbonitriding furnace
In this furnace quenching takes place in an oil bath maintained under vacuum. This improves safety and working conditions during heat treatment of workpieces. Both the conventional KCF furnace with a spray guard and the reduced-pressure quench KCF furnace use Moldatherm® heating elements. This ensures excellent temperature uniformity in the furnace and low energy consumption. Fast gas exchange is also guaranteed.
- ● Up to two oil-bath agitators can be installed.
- ● A continuously operating version is also available.
- ● An optional cooling chamber can be ordered. Models for carbonitriding and soft-nitriding are available as special equipment.
- ● These systems can optionally be fuelled by gas.
Through-feed furnaces with chain conveyor for carbonitriding
The chain conveyor system used here is very reliable and well suited for heat treating small steel parts. The belt is driven by a drive roll at the furnace outlet. The energy-efficient muffle furnace again uses Moldatherm® heating elements.
Two-stage nitriding furnace
The hardening process by nitriding in this furnace is carried out in two stages. This shortens heating and cooling times and increases throughput. It also reduces the amount of personnel needed to operate the furnace.
