Rückfeinen (Stahl)

Description: The purpose of normalising Steel (Annealing to relieve stresses) is to create a structure that is as fine-grained as possible and can be reproduced if necessary. It is often used on castings that have an irregular grain after casting (for example, Widmannstätten structure with dendrites or a fine-grained boundary area and a coarse-grained core). The aim is to produce a uniform (micro)structure with good Strength and formability. Normalising can be used, for example, to eliminate or reduce Work Hardening and internal stresses. It is performed at a temperature just above the upper transformation point because the first step is to fully austenitise the material. However, the fine-grained structure that is created exhibits grain growth. It is therefore rapidly cooled up to the end of transformation The structure is influenced by heat dissipation, i.e. also by the mass and surface of the workpiece. It is not possible to normalise ferritic or austenitic stainless steels that do not undergo conversion during the temperature change.