TY - CONF A1 - Kromm, Arne A1 - Kannengießer, Thomas T1 - Online-Observation of Martensite Formation by combined use of Synchrotron Diffraction and Dilatometry T2 - Proceedings of Visual-JW 2019 & WSE 2019 N2 - Welding residual stress engineering by means of an adjusted martensite phase transformation would be highly attractive as detrimental tensile residual stresses may be prevented already during welding without time and cost intensive post processing. The present study shows a synchrotron diffraction analysis of a martensitic steel subjected to thermo-mechanical load cycles. Experiments were conducted regarding the microstructural strain response during the austenite to martensite transformation. The strains are a function of the temperature and the specific loads applied during cooling. The relation between the transformation plasticity of the material, the amount of martensite formed and the arising strains can thus be assessed. The lattice plane specific strains were compared to experimental findings from (macro) dilatation tests. It is shown that the microscopic material behavior differs remarkably from the one observed on the macroscopic scale, what leads to characteristic residual stresses in the material. T2 - Visual-JW 2019 & WSE 2019 The 5th International Symposium on Visualization in Joining & Welding Science through Advanced Measurements and Simulation & The 8th International Conference of Welding Science and Engineering CY - Osaka, Japan DA - 21.11.2019 KW - Martensite KW - Synchrotron KW - Dilatometry KW - Residual stress KW - Phase transformation PY - 2019 SP - 83 EP - 84 PB - SEIEI Printing Co., Ltd CY - Osaka, Japan AN - OPUS4-49770 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -