P 890 – Forming behavior of Tailor Welded Blanks of high-strength multi-phase steels – characterization, modelling und verification
The use of Tailor Welded Blanks (TWB) out of high strength steel is currently rare in the automotive industry due to the fact that the weld line modelling is not precise in the forming simulations. The aim of this project was the characterisation of the weld line concerning its forming properties, the modelling of the weld line in different ways and the verification with real forming experiments. In this project, which was done in cooperation with ThyssenKrupp Steel Europe, TWB out of three common steel grades were characterized. In this project the high strength steel grades HCT980X, HCT600X and HX300LAD were used. With this, the weld line could be characterized and a flow behavior could be evaluated. The modelling of the weld line was verified with real formingexperiments. Therefore, two different forming tools were used, in which high loads could be realized in the weld line to get conclusions concerning its forming behaviour. There, the linear weld line was positioned in different regions with differences in the applied load and the weld line behaviour was analysed (fracture, weld line movement). The forming experiments showed that TWBs made out of HCT600X/HCT980X and HCT600X/HX300LAD can be formed without failure if the weld line does not cross critical areas in the tool. The modelling of the weld line itself with an own flow curve can improve the accuracy of the simulation results.
Main results are:
- TWB made out of multi-phase high strength steel
can be formed without failure
- To realise an optimal forming result, the weld line
should be positioned in non-critical areas of the
tool. The design should be done in simulation
based investigations with high accuracies.
The research project was carried out at Institut für Umformtechnik und Leichtbau der Technischen Universität Dortmund and at ThyssenKrupp Steel Europe AG, Duisburg. FOSTA has accompanied the research work and has organized the project funding from the Foundation for Steel Application Research.
Only available in german language.
T. Mennecart, A. Güner, A. E. Tekkaya, M. Linnepe, A. Marx