A phenomenological macroscopic plasticity model is developed for steels that exhibit strain-induced austenite-to-martensite transformation. The model makes use of a stress-state dependent transformation kinetics law that accounts for both the effects of the stress triaxiality and the Lode angle on the rate of transformation. The macroscopic strain hardening is due to nonlinear kinematic hardeni...

Neutron diffraction spectra were obtained during various stages of a reversible stress-induced austenite to martensite phase transformation in superelastic NiTi. This was accomplished by neutron diffraction measurements on bulk polycrystalline NiTi samples simultaneously subjected to mechanical loading. Analysis of the data was carried out using individual lattice plane ~hkl! reflections as wel...

SUS440 is a high-carbon stainless steel, and its martensite matrix has high heat resistance, high corrosion resistance, and high pressure resistance. It has been widely used in mechanical parts and critical materials. However, the SUS440 martempered matrix has reliability problems in thin plate applications and thus research uses different austempering heat treatments (tempering temperature: 20...

Depending on the starting equilibrium temperature, the application of a magnetic field on a sample of Ni–Mn–Sn produces sample heating or cooling during adiabatic experiments. The competition between endothermal and exothermal effects is observed close to the martensite-to-austenite magnetostructural phase transition. A model assuming the coexistence of two phases and a field dependence of thei...

The medium Mn steels are gaining increasing attention due to their excellent combination of mechanical properties and material cost. A cold-rolled 0.1C5Mn medium Mn steel with a ferrite matrix plus metastable austenite duplex microstructure was resistance spot-welded with various welding currents and times. The nugget size rose with the increase of heat input, but when the welding current excee...

The aim of this work is to provide a novel understanding pseudoelasticity mechanisms in an FeMnSi-based shape memory alloy and utilize the identified parameters control enhance mechanical behavior alloy. was processed by employing caliber rolling equivalent strain 0.25 at room temperature. Various heat treatments from 530 1000 °C were applied study microstructural evolution during short-term po...

For the mechanical behavior of steels with metastable austenite, it was widely accepted that high strain rates could weaken deformation-induced martensitic transformation (DIMT) and reduce work-hardening behavior. This limits application these for energy-absorption applications, e.g., impact conditions. However, mechanism strain-rate dependent DIMT is still not well understood greatly limited f...

Metastable austenitic CrNi steels undergo phase transformation when loaded or deformed plastically. In the current work a macroscopic and phenomenological constitutive model is presented to strain induced of austenite martensite. The approach based on previous works Olsen Cohen [1] & Stringfellow et al. [2]. kinetics modelled assumption that intersections shear bands in phase, act as potential ...

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...

To clarify the contribution of martensite increase to work-hardening during transformation-induced plasticity (TRIP), changes in local strain distribution with tensile deformation were investigated for dual-phase steels different volume fractions ferrite using precise marker method. Particular attention was paid and stress bearing by deformation. The method is especially useful analysis multiph...