In recent years, there has been a growing interest in steels of multi-phase structures, composed of a ferritic matrix, in which islets occur, that contain bainite-B, martensite-M and the untransformed austenite-A 1-9 . The multi-phase structure of steel with untransformed austenite promotes the increase of plasticity induced by the phase transformation – the TRIP effect 3-4, 6-8 . In steels con...

1) Hubei Collaborative Innovation Center for Advanced Steels, International Research Institute for Steel Technology, Wuhan University of Science and Technology, Wuhan, 430081 China. 2) Institute for Frontier Materials, Deakin University, Geelong, Victoria, 3226 Australia. 3) Department of Engineering and Innovation, The Open University, Walton Hall, Milton Keynes, MK7 6AA UK. 4) Department of M...

The processing of advanced multiphase high strength steels often includes isothermal treatments around the martensite start temperature (Ms) for achieving a refined microstructure comprising bainite-austenite and/or bainite-martensite-austenite phase constituents. objective this research work was to investigate structure-property relationship medium carbon, high-silicon DIN 1.5025 steel (Fe-0.5...

A Cu precipitation-mediated austenitic transformation during ageing treatment of a 15–5 PH stainless steel is revealed through atom probe tomography, in situ synchrotron X-ray diffraction and computational thermodynamics kinetics. The proposed to occur the pathway: precipitation at martensite/retained austenite interfaces or martensite lath boundaries ? partitioning stabilizing elements towards...

We evaluated friction fatigue-induced changes in the microstructure and residual stress of carburized steel. By eddy current testing (ET) x-ray diffractometry (XRD), voltage rate (after/before fatigue testing) obtained by ET had a strong correlation with retained austenite phase full width at half maximum XRD. The results are useful for analysis damage

In situ three-dimensional (3-D) X-ray diffraction experiments have been performed at a synchrotron source on low-alloyed multiphase TRIP steels containing 0.25 wt.% Si and 0.44 wt.% Al and produced with different bainitic holding times, in order to assess the influence of the bainitic transformation on the thermal stability of individual austenite grains with respect to their martensitic transf...

Stress–strain behavior of a low carbon alloy multiphase steel with ferrite, tempered bainite, and retained austenite was studied at different cryogenic temperatures. Results indicated that both strength ductility were enhanced decreasing tensile testing temperature. The enhancement attributed to the decreased mechanical stability temperature, resulting in sufficient transformation induced plast...

This paper reports on the precipitation behaviour and microstructural evolution in ~20% cold rolled NbMoV and V single microalloyed low carbon steels during intercritical annealing. The microstructure and precipitation behaviour were studied by optical and scanning/transmission electron microscopy and microanalysis, X-ray diffraction technique and Vickers hardness testing. After intercritical a...

The phase composition of nanobainitic steel 0.56–0.60%C, 1.68–1.95%Mn, 1.58–1.80%Si, 1.30–1.47%Cr, 0.57–0.75%Mo is described in this paper. controlled order to obtain diversified mechanical properties for specific applications, such as armor plates. effect temperature and time isothermal heat treatment on both the microstructure were determined. Dilatometric studies, well measurements volume fr...

The aim of this work was to compare the microstructures 17-4PH martensitic stainless steels (MSSs) obtained by conventional manufacturing (CM), and additive (AM) using laser beam melting (LBM) process. Both materials were studied after same H900 heat treatment. Significant differences in microstructure observed between two MSSs, with a higher austenite content for AM-H900 sample, as compared CM...