Influence of initial state and chemical composition on the hardening and softening kinetics in hot metal forming

Philipp Hagemann, Rudolf Kawalla, Werner Jungnickel, Matthias Schmidtchen

Technische Universität Bergakademie Freiberg – Institut für Metallformung, Freiberg, Germany.

DOI:

https://doi.org/10.7494/cmms.2011.1.0327

Abstract:

Materials in hot metal forming are suspended to a series of plastic deformation until they obtain their final shape and geometry. In classical processing routes a sequence of cooling and reheating and therefore phase transformation is settled prior to deformation after solidification. The recent development in process philosophy is the direct linkage of solidification and deformation without an intermediate step of reheating from low temperatures. Initial states, especially structure and precipitation state, of reheated and direct-cast materials have a substantial impact on performance and behaviour before, during and after deformation, in particular the hardening and softening kinetics. This applies in particular on the micro-alloyed steels, where precipitation state has a markedly dependence on the prehistory. The influence of the initial state prior to deformation on flow stress, softening kinetics in particular the recrystallisation kinetics, and the precipitation kinetics is shown using the example of several steel grades. Differences in deformation behaviour are also documented with semi empirical models with their specific coefficients.

Cite as:

Hagemann, P., Kawalla, R., Jungnickel, W., & Schmidtchen, M. (2011). Influence of initial state and chemical composition on the hardening and softening kinetics in hot metal forming. Computer Methods in Materials Science, 11(1), 154 – 160. https://doi.org/10.7494/cmms.2011.1.0327

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