TY - GEN

T1 - Experimental and numerical investigation of dynamic transformation induced plasticity during hot forming

AU - Behrens, Bernd-Arno

AU - Uhe, Johanna

AU - Wester, Hendrik

AU - Kock, Christoph

AU - Heimes, Norman

N1 - Publisher Copyright: © 2024 TANGER Ltd., Ostrava.

PY - 2023/6/13

Y1 - 2023/6/13

N2 - Hot forging processes are influenced by numerous thermo-mechanical-metallurgical material phenomena, which interact strongly. In particular, the strains due to transformation-induced plasticity (TRIP) occurring during the forming process have a considerable influence on the distortion and residual stresses of the components. As TRIP strains are anisotropic they depend on the orientation and magnitude of the stress states superimposed to the phase transformation during cooling. By numerical modelling the impact of the TRIP effect can be analysed and taken into account during process design. However, required material data are poorly accessible to non-existent in literature. Therefore, this work focuses on the determination of characteristic values of TRIP for the material AISI 52100 considering dynamic effects. Tests were performed using hollow specimens which were thermo-mechanically loaded. An external stress was applied shortly before the start of the transformation and, in the case of reversible transformation plasticity, selectively released during the transformation phase. In this way, it was possible to determine phase-specific as well as load-dependent reversible transformation plasticity effects. The determined values for TRIP effect with and without backstress were transferred to a FE simulation and successfully validated with an experimental comparison. The material models and subroutines created are now to be validated on the basis of experimental forging tests by comparing distortion and residual stresses.

AB - Hot forging processes are influenced by numerous thermo-mechanical-metallurgical material phenomena, which interact strongly. In particular, the strains due to transformation-induced plasticity (TRIP) occurring during the forming process have a considerable influence on the distortion and residual stresses of the components. As TRIP strains are anisotropic they depend on the orientation and magnitude of the stress states superimposed to the phase transformation during cooling. By numerical modelling the impact of the TRIP effect can be analysed and taken into account during process design. However, required material data are poorly accessible to non-existent in literature. Therefore, this work focuses on the determination of characteristic values of TRIP for the material AISI 52100 considering dynamic effects. Tests were performed using hollow specimens which were thermo-mechanically loaded. An external stress was applied shortly before the start of the transformation and, in the case of reversible transformation plasticity, selectively released during the transformation phase. In this way, it was possible to determine phase-specific as well as load-dependent reversible transformation plasticity effects. The determined values for TRIP effect with and without backstress were transferred to a FE simulation and successfully validated with an experimental comparison. The material models and subroutines created are now to be validated on the basis of experimental forging tests by comparing distortion and residual stresses.

KW - AISI 52100

KW - FE-simulation

KW - Hot forging

KW - phase transformation

KW - transformation-induced plasticity

UR - http://www.scopus.com/inward/record.url?scp=105003709893&partnerID=8YFLogxK

U2 - 10.37904/metal.2023.4639

DO - 10.37904/metal.2023.4639

M3 - Conference contribution

T3 - METAL - International Conference on Metallurgy and Materials, Conference Proceedings

SP - 164

EP - 169

BT - METAL Conference Proeedings

ER -