Ossama Dreibati Physical welding simulation of the cold crack susceptibility Band 8 ISBN: 978-3-8440-3133-1 Price: 48,80 € / 61,00 SFR |
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The trend towards more material and energy efficiency through lightweight design requires the use of high strength steels. These steels tend to form brittle microstructures during welding processes and therefore, they are particularly susceptible to cold cracks. Coldcracksare problematic from the quality point of view. They arise in the welded joints during cooling when the local combination of brittle microstructure, tensile stresses and diffusible hydrogen reaches a criticallirnit. In this thesis, a cold crack assessment method is presented and validated. It is based on a multi-step approach. Critical combinations of the three cold crack influence parameters - brittle microstructure, tensile stresses and hydrogen concentration - are identified using the enhanced simulation and testing center „Gleeble 3500“. The experimental results form the basis of a material specific cold cracking criterion which are implemented in a newly developed cold crack simulation tool. In addition to the cold crack criterion, the locally FE-calculated weid cold crack influence parameters are introduced to the cold crack simulation tool. The cold crack susceptibility of the local FE-calculated cold crack influence parameters is then quantitatively predicted by means of the cold crack criterion. The transferability of the identified cold crack criterion on complex welded components is proved. | |
Source: Welding and Cutting: Technical journal for welding and allied processes, Januar 2015, S.62 | |
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