The effect of silicon, aluminium and phosphor on the dynamic behaviour and phenomenological modelling of multiphase TRIP steels

Abstract

Multiphase TRansformation Induced Plasticity (TRIP) steels combine excellent ductility and high strength, making them ideally suited for shock absorbing parts in the automotive industry. When designing structures for impact, an understanding of the mechanical properties of materials under high strain rate conditions is essential. An extensive experimental program using a split Hopkinson tensile bar set-up was established in an effort to investigate the dynamic properties of various TRIP steel grades. Four different TRIP steels are described with varying contents of the alloying elements silicon, aluminium and phosphor. Moreover, several phenomenological models describing the strain rate and temperature-dependent mechanical behaviour are validated. TRIP steel grades in which aluminium is the main alloying element show high elongation values, whereas a high silicon content results in an increase in strength. The widely used Johnson-Cook model can describe the behaviour of TRIP steels and provides the opportunity to study its material and structural response.