RIKTVBC

Purpose and goal

Straightening after heat treatment i performed on a large number of components. Heat treatment often results in shape distortions which have to straightened away. Straightening has a negative effect on fatigue strength of a component since the residual stress state is changed unfavourably in parts of the component. In order to reduce this negative effect the change in residual stresses and the corresponding reduction in fatigue strength is studied in detail. The objective is to formulate a straightening process with minimal impact.

Results and expected effects

Expected results is a detailed understanding of the effect of straightening on fatigue strength and guidelines for how a straightening operation ought to be conducted in order to reduce the negative impact to a minimum.

Approach and implementation

Experiments (heat treatment, straightening, fatigue tests) in order to understand the effect of straightening on fatigue strength. FEM-simulations as a basis for guidelines for straightening.