Micro structure and temperature dependent failure modelling for analysis of hot sheet metal formning

Important results from the project

The project concerns determination of models for simulation of press hardening of sheet material which is an important process for manufacturing of protective components in the automotive industry. In this process the material undergoes deformation under rapid cooling causing phase transformations. Fracture of the material in the forming tool must be avoided and therefore fracture criteria for the material at all stages present in the process are of great interest in order to develop and optimise the manufacturing process. A comprehensive experimental programme regarding strain rate and temperature history is included in the project. Modelling based on experimental results is also an important part. A model covering the stages that are present in the process will be developed, implemented and validated on a specially designed component. Finally the model will be used for simulation of the industrial press hardening operation in order to develop and optimise the production process.

Expected long term effects

Heat treatment is a very important industrial procedure in the manufacturing of boron-alloyed ultra-high strength components. The temperature history in the press-hardening process changes the mechanical properties of the sheet material continuously during the process. Proper simulation of the production process is essential in order to optimize production parameters and obtain good efficiency and avoid material fracture in the tools. Simulation models will be developed that can accurately predict fracture for different material states regarding temperature history, microstructure and strain rate. These models will be implemented in computer codes so that the industrial production process can be realistically simulated with good accuracy.

Approach and implementation

The project will be carried out in close collaboration between Gestamp HardTech and Luleå University