A Computational Investigation on Bending Deformation Behavior at Various Deflection Rates for Enhancement of Absorbable Energy in TRIP Steel

Abstract

Transformation-induced plasticity (TRIP) steel might have a high energy-absorption characteristic because it could possibly consume impact energy by not only plastic deformation but also strain-induced martensitic transformation (SIMT) during deformation. Therefore, TRIP steel is considered to be suitable for automotive structures from the viewpoint of safety. Bending deformation due to buckling is one of the major collapse modes of automotive structures. Thus, an investigation on the bending deformation behavior and energy-absorption characteristic in TRIP steel at high deformation rate is indispensable to clarify the mechanism of better performance. Some past studies have focused on the improvement of mechanical properties by means of SIMT; however, the mechanism through which the energy-absorption characteristic in steel can be improved is still unclear. In this study, the three-point bending deformation behavior of a beam specimen made of type-304 austenitic stainless steel, a kind of TRIP steel, is investigated at various deflection rates by experiments and finite-element simulations based on a constitutive model proposed by one of the authors. After confirming the validity of the computation, the rate-sensitivity of energy absorption from the viewpoint of hardening behavior is examined and the improvement of the energy-absorption characteristic in TRIP steel including its mechanism is discussed.

An Experimental Study on Strain Rate Sensitivity of Strain‐induced Martensitic Transformation in SUS304 by Real‐time Measurement of Relative Magnetic Permeability

“…The rate sensitivity of austenitic stainless steel is, thus, an important research object. Previous studies have described the rate sensitivity of mechanical characteristics in austenitic stainless steel; research works have also confirmed the mechanical properties of these materials per the strain‐induced martensitic transformation (SIMT) under inelastic deformation . In other words, SIMT is directly related to the reliability of the steel.…”

Damage development during the strain induced phase transformation of austenitic stainless steels at low temperatures

“…Therefore, the plastic behavior of these stainless steels has been extensively investigated to understand how the continuously reforming bi-phase material responds to the applied loads. Majority of the studies on the topic evaluated the two, kinetics of the phase transformation [1][2][3][4][5] and the hardening behavior of the material during transformation [2,4,[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. However, another important issue would be the damage growth, decreasing of the load-carrying capability and fracture of the material during and after the phase transformation.…”

The Influence of the Substitution of Si by Al on the Properties of Hot Rolled C-Mn-Si TRIP Steel

“…They must enable light weight construction by a combination of excellent mechanical properties yet at an affordable price [1][2][3]. To date, transformation-induced plasticity (TRIP) steels have been developed [4][5][6]. TRIP steels have a multi-phase microstructure, including polygonal ferrite, bainite, martensite and retained austenite (RA) [7].…”