Measurement and prediction of residual stresses for robust and flexible processes

Purpose and goal

The aim of the project was to significantly improve the possibility of delivering high strength niche materials with an optimised residual stress state to customers. The specific goal according to the project proposal was development of models for three process steps (quenching, skin pass rolling and roll levelling) for high strength steels in a strip mill at one of the project partners. This has been achieved via close collaboration between three research providers and the models can now be applied and further developed within the industrial process development work.

Expected results and effects

The result of the project is that there are now available models for simulation of process modifications in three steps in a strip mill. The potential for further refinement in some area has been identified, but the models are now useful for process development work. The project addresses three goals within Agenda step 4 Increase flexibility (4A, 4B, 4H). Broader relevance within the strategic innovation area Metallic Materials has been achieved by participation of a further three steel producers.

Planned approach and implementation

The original plan has been followed. Two materials have undergone extensive thermomechanical characterization in a Gleeble and dilatometer in order to obtain necessary materials parameters. Residual stresses have been measured after different process steps and during loading of an entire coil section in a specially-built rig. A new materials model for phase transformations has been implemented and finite element models for the actual processes have been developed