Wat kan Dominial Vacuüm harden of carboneren?

  • Dominial kan carboneren variërend tussen 0,1 en 6 mm diep
  • We kunnen tot een afmeting van Ø 2600 * 3500 mm kan behandelen.
  • Onderdelen behandelen met een stukgewicht tot 20.000 kg.
  • EHT-curves maken door Geavanceerde apparatuur
  • Dominal heeft het proces volledig geautomatiseerd wat betekend dat we nauwkeurig de laagdikte en koolstof percentage kunnen bepalen
  • Dominal beschikt over 10 Gasretort Carboneer ovens.

Vacuum Carburizing (LPC)

The process

Vacuum carburizing with quenching belongs to the process group of case hardening. Compared to case hardening under protective atmosphere the advantages of vacuum technology can be used. Case hardening – also under vacuum – is classed as a thermochemical process. In this process, the surface layer of a component or tool is carburized by means of a medium that emits carbon and subsequently quenched. The effect of this is to improve the mechanical properties (e.g. wear characteristics) of the component’s surface layer. After the carburized components have undergone hardening, tempering is generally required, to relieve any stresses created during hardening, and to achieve the required handling strength. Quenching media is oil in VTN´s technology. Partial case hardening is also possible, using suitable isolating methods

Customer information required for heat treatment:

Material designation

Case depth in mm (CHD)

Target values for surface hardness

Insulation requirements, where relevant (e.g. in the form of a workpiece drawing indicating sections that must not undergo hardening)

Suitable materials

Case hardening steels are construction steels with a relatively low carbon content, whose surface layer is generally carburized or carbonitrided prior to hardening. The carbon content of case hardening steels is generally below that of hardened and tempered steels, i.e. less than 0.25%.

Benefits of this heat treatment

High uniformity carburizing within a batch and batch-to-batch operation.

High precision control of carbon transfer and case depth.

Enhanced cleanliness of products.

Improved mechanical properties, elimination of inter-granular oxidation layer, improved fatigue properties.

Good uniform carburizing for narrow gaps and deep blind holes.

Carburizing temperatures up to 1.050° possible.

Environmentally friendly, no CO2- emission.

Complies with high health&safety standards.

Vacuum hardening up to 1,300°C

The process

Hardening is a heat treatment that consists of austenitizing and cooling, performed under conditions that allow an increase in hardness to be brought about by a more or less complete transformation of the austenite generally into martensite.

Austenitization is the stage of the process in which the workpiece is brought to austenitizing temperature and the steel matrix becomes austenitic through complete phase transformation and carbide dissolution. Austenitizing is followed by cooling. To allow the entire workpiece to take on a martensitic microstructure, the speed of the temperature drop must be greater than the critical cooling speed of the respective steel.

Cooling can take place in a variety of media; these differ characteristically in terms of their cooling effect in the various temperature ranges.

After hardening, the microstructure of so-called hypereutectoid steels is usually composed of martensite plus residual austenite plus carbide. Great importance is attached to the proportions of these phases, for instance in the heat treatment of tool steels, because characteristics such as resistance to wear and dimensional accuracy are affected by the structural state after hardening. Following hardening, tempering is necessary to relax the martensitic microstructure and to set the required strength. At low tempering temperatures (generally up to 250°C), the martensitic microstructure can be impacted on without any great compromise to hardness. Only at higher temperatures (dependent on the material, but as a rule at T>250°C), is structural relaxation accompanied by an appreciable loss in hardness. The component’s hardness properties can be adjusted by way of the tempering temperature. At considerably higher tempering temperatures (from around 400°C), the process is referred to as steel hardening and tempering. It is then possible to adjust both hardness and mechanical properties of the steel.

Customer information required for heat treatment

The following information is required in all cases:

Material designation

Required hardness

Processing state of the workpiece upon submission (e.g. preliminary hardening and tempering)

benefits of this heat treatment

Hardening is used to give components and tools sufficient hardness and strength to withstand mechanical stress, such as static or dynamic deformation through tension, pressure, bending or wear.

Suitable materials

In principle, any steel can be hardened to varying degrees. However, hardenability depends chiefly on the steel’s chemical composition. Hardenability is the ability of a steel to assume an increased hardness to a greater or lesser depth in the zone close to the surface. The term hardenability refers to both the extent and the distribution of the increase in the workpiece’s  hardness. As a general rule, carbon is responsible for hardness. If there is no carbon in the steel (min. 0.22%C), it will hardly be possible to achieve an increase in hardness. Besides carbon, the quantity, type and number of alloy elements in the steel have an effect on hardness, toughness, through-hardenability, resistance to wear, and other mechanical values.