Recently, with the requirement of lighter weight and more safety for a design of automobile, energy absorption capability of structural materials has become important. TRIP (Transformation-induced Plasticity) steel is expected to apply to safety members because of excellent energy absorption capability and ductility. Past studies proved that such excellent characteristics in TRIP steel are domi...

A steel has recently been designed to benefit from the deformation induced transformation of retained austenite present in association with bainitic ferrite. It has as its major microstructural component, dendrites of d-ferrite introduced during solidification. The d-ferrite replaces the allotriomorphic ferrite present in conventional alloys of this kind. The authors examine here the stability ...

This work aims at investigating the spot weldability of a new advanced Quenching and Partitioning (Q&P) steel and a Transformation Induced Plasticity (TRIP) steel for automotive applications by evaluating the effects of the main welding parameters on the mechanical performance of their dissimilar spot welds. The welding current, the electrode tip voltage and the electrical resistance of sheet s...

Fundamental Aspects of Materials and Energy, Delft University of Technology, Mekelweg 15, Delft, 2629 JB, The Netherlands, Materials innovation institute, Mekelweg 2, Delft, 2628 CD, The Netherlands, Dalton Cumbrian Facility, Westlakes Science and Technology Park, The University of Manchester, Moor Row, Cumbria CA24 3HA, UK, Department of Materials Science and Engineering, Delft University of T...

Recent research suggests that extraordinary combinations of strength and ductility can be achieved in the so–called δ–TRIP steels, which contain ferrite, bainite and austenite. A part of the reason for the ductility of almost 40% elongation at a strength of some 900MPa, is believed to be the optimal stability of the austenite to plastic deformation. We demonstrate here that mechanical stabilisa...

The decomposition of martensite during tempering or ageing is an important phenomenon as it leads to changes in the mechanical properties. These changes could take place during both steel manufacturing or in-service. Thus, their understanding is required to predict the material performance. Recent advances in the development of local electrode atom probes has led to a significant increase in th...

Hexagonal close-packed (hcp) iron carbides play an important role in steel processing and in steel products. The recent discovery of novel ultrafine (2-5 nm) iron carbide (ε'-Fe2+xC) precipitates in TRIP steel sheds a new light on the hcp family of carbides. Here we present a first-principles study on the relative stability, and the electronic, magnetic properties of the ε'-Fe2C phases. Differe...

In this paper we present a new polynomial function for calculating the local phase transformation temperature (Ae3 ) between the austenite+ferrite and the fully austenitic phase fields during heating and cooling of steel:[Formula: see text] The dataset includes the terms of the function and the values for the polynomial coefficients for major alloying elements in steel. A short description of t...