High quality plates made of hot working or low temperature steel grades for pressure vessels or high strength grades in larger plate thicknesses are subjected to additional heat treatment by normalising or quenching and tempering. Two heating furnaces and a quenching unit are available for these processes.

Normalising comprises heating of a plate to around 900 degrees Celsius followed by cooling in still air. The double transition results in a generally more homogeneous and finer grain structure with improved mechanical-technological properties.

The two-step process of quenching and tempering consists of hardening by austenitising the plate at 900 degrees and quenching in water. The plate is clamped in the hardening unit to avoid warping during quenching.

The desired material properties are achieved with subsequent tempering. This process results in a material with very fine-grained and homogeneous structure as well as high strength and proper toughness.