The use of FINECARB® technology allows to obtain optimal parameters of the surface layer because of the elimination of internal oxidation and uncontrolled, unfavourable precipitation. An additional effect is the reduction of deformation of elements during their heat treatment. We offer the implementation of processes in single-chamber vacuum furnaces, in which both the carburizing and hardening processes take place in the same chamber, as well as in two-chamber vacuum furnaces, where the carburizing process is carried out in one chamber, the so-called "Heating chamber", and the hardening process in the second chamber, the so-called "Cooling chamber", connected with a quenching bath. Low-pressure carburizing of steel with the FineCarb® technology guarantees the achievement of the assumed thickness of the surface layers in a much shorter time compared to gas carburizing, as well as full control and repeatability of the processes. After the carburizing stage, we can harden in vacuum oil or nitrogen in high pressure. 

The purpose of hardening is to obtain a hard martensitic or sometimes bainitic structure. These structures can only arise from austenite, therefore, in the process of hardening the steel, it must be heated to the temperature at which austenite is formed. Hypereutectoid steels are heated to temperatures from 30 to 50°C above Ac3, while hypereutectoid steels- to temperatures from 30 to 50°C above Ac1. Hardening of hypereutectoid steels with heating to the austenite / cementite two-phase range occurs because the hard cementite provides high abrasion resistance. Dissolving cementite while heating the steel in the hardening process would be pointless, as it would lead to a reduction in hardness due to an increase in the amount of residual austenite and loss of strengthening with cementite particles. At the same time, there would be an increase in the austenite grain, an increase in scale losses and a higher energy consumption (higher furnace temperature). In the process of steel hardening, it should be cooled from the austenitizing temperature at a rate which ensures that the changes in the diffusion range are avoided (at a rate greater than or equal to the so-called critical rate at which martensitic or bainitic transformation occurs). A simple solution to avoid the formation of high stresses causing deformation of the workpiece, and sometimes also its fracture, is gradual hardening, which consists of holding the detail at a temperature above Ms until the temperature equalizes in the cross-section and then on slow cooling, ensuring the simultaneous occurrence of martensitic transformation in the entire cross-section.   

Depending on the type of material, the shape and cross-section of the details as well as the operational requirements, hardening can be performed in oils or gases under high pressure. It ensures smaller and more repeatable deformations and, consequently, allows to reduce the grinding allowance. 

After hardening, steel gains hardness and strength, its yield point and elasticity increase. However, its impact strength, elongation, contraction and machinability decrease.

Steels with austenitic structure, as well as other alloys - mainly of non-ferrous metals - which do not show allotropic changes but are characterized by variable solubility of one of the components in a solid solution, can be subjected to precipitation hardening. 

We offer processes that are combined technological operations:  
• supersaturation
• aging

Supersaturation
It consists of heating the alloy to a temperature higher by approx. 30÷50°C than the limit of solubility to dissolve the separated component (in steels, most often tertiary cementite) in a solid solution, heating at this temperature and then cooling rapidly. As a result of supersaturation, the alloy obtains a single-phase structure. In the case of austenitic steels, the structure is austenite supersaturated with carbon. The strength properties of steel after supersaturation are slightly reduced, but plastic properties increase.   

Aging
It consists of heating the previously supersaturated alloy to a temperature lower than the limit of solubility, heating at this temperature and cooling it down. During the aging process, the excess component in the supersaturated solid solution is released in the form of highly dispersed phases. In some cases, the aging involves intermediate phases and Guinier-Preston zones, in which they segregate atoms dissolved in the solvent. Aging causes strengthening, shown by an increase in strength properties and a decrease in plastic properties. When the temperature is too high, the aging effect occurs, consisting in coagulation of the precipitates and the loss of their coherence, which does not increase the hardness in relation to the supersaturated state, but on the contrary - reduces it. Sometimes aging occurs at room temperature, then it is called spontaneous aging. 

Aging can also be an undesirable process, e.g., in deep drawing sheets and boiler steels, as it reduces plastic properties and increases brittleness.  

A method of heat treatment of the material, which usually involves heating the steel to a specific temperature, heating it at this temperature and cooling it to obtain structures close to the equilibrium state. One can distinguish between recrystallization annealing, homogenization, stress relief, complete, isothermal and spheroidizing annealing. In the field of annealing, we carry out orders from a wide range of services.