Vacuum annealing
Stress relief annealing
Soft-annealing
Normal annealing

In order to prepare materials with a thermodynamic imbalance for further treatment, we apply the process of artificial ageing: Through heating to moderate temperatures (approx. 250 °C), cooling to very low temperatures or oscillating within a temperature range.

Through normalizing, we eliminate structural irregularities, and the result is a fine-grained, even structure with optimal resistance and deformability properties - very important for cast steel pieces or for welded constructions.

Stress relief annealing (see figure above) is usually carried out in a temperature range of 550-650°C, followed by slow cooling for relieving internal stresses, without significantly changing the present properties. For further treatment and subsequent heat treatments, such stresses are otherwise released and result in distortions.

With low-stress annealing before finishing a work piece, the subsequent distortion is levelled.

Soft-annealing does not take the structure before soft-annealing into account, or how this should be after annealing. What's important is the alteration of the tensile strength or hardness respectively. Annealing for several hours to 680 °C-750 °C, depending on the carbon content, renders the work piece completely stress-free, to enable proper further treatment. Soft-annealing is mainly used during the treatment process of a work piece.

Tempering results in an improvement of the mechanical properties (firmness, toughness) through long-term annealing at temperatures between 700 °C and 1050 °C. The result is annealed cast iron.