Experimental-numerical approach to efficient TTT-generation for simulation of phase transformations in thermomechanical forming processes

5th International Conference Recent Trends in Structural Materials

Behrens, B.-A.^1 ; Chugreev, A.^1 ; Kock, C.^1

IFUM - Institut für Umformtechnik und Umformmaschinen, Leibniz Universitat Hannover, An der Universitat 2, Garbsen

30823, Germany^1

关键词: A-thermomechanical process;    Adjustment parameter;    Manufacturing process;    Numerical approaches;    Numerical procedures;    Residual stress state;    Temperature profiles;    Time temperature transformation diagrams;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/461/1/012040/pdf
DOI  :  10.1088/1757-899X/461/1/012040

来源: IOP

【 摘 要 】

Residual stresses in components are an important issue in most manufacturing processes, as they influence the performance of the final part. Regarding hot forming processes there is a great potential of defining a targeted residual stress state, due to numerous adjustment parameters like deformation state or temperature profile. In order to ensure appropriate numerical modelling of resulting residual stresses in a thermomechanical process, comprehensive material data regarding phase transformation are required. This paper presents an experimental-numerical procedure to efficiently determine time-temperature-transformation diagrams for cooling simulations after hot forming. The transformation behaviour of the steel alloys 42CrMo4 and 100Cr6 is determined by experiments as well as FE-simulations. Finally, the simulation model is validated by dilatometric experiments and metallographic investigations.