In material selection, especially in low temperature conditions, one of very important factors it is a ductile to brittle transition temperature, i.e. the temperature when material becomes too brittle to use. In this paper transition temperature determined by impact energy in temperature interval from –196 to +100°C of unalloyed austempered ductile iron with different microstructures have been ...

High silicon (>1.5%) steels with different compositions were isothermally transformed to bainite at 220 and 250 ◦C to produce what is often referred to as nanostructured bainite. Interrupted tensile tests were carried out and the retained austenite was measured as a function of strain. Results were correlated with tensile ductility. The role of retained austenite stability is remarkably underli...

Duplex stainless steels (DSSS) have a microstructure composed of ferrite and austenite phases that gives them a very good combination of mechanical and corrosion properties. These steels are desirable for many applications in the chemical and petrochemical industries. In the present study, a type of stainless steel was cast, solution annealed at 1200°C for 60 min and then quenched in water. Ini...

Thermodynamically consistent, three-dimensional (3D) phase field approach (PFA) for coupled multivariant martensitic transformations (PTs), including cyclic PTs, variant– variant transformations (i.e., twinning), and dislocation evolution is developed at large strains. One of our key points is in the justification of the multiplicative decomposition of the deformation gradient into elastic, tra...

In the present research, the effect of the homogenization process and annealing temperature were investigated for the 1.4470 ferritic-austenitic stainless steel in the as-cast condition. In this regard, microstructural evolutions, hardness, and impact energy of the steel was evaluated with different heat treatment conditions. The results show that the minimum volume fraction of austenite phase ...

The orientation of crystals of allotriomorphic ferrite in austenite has been investigated in order to understand the mechanism by which particular relationships are favoured over others via a process known as “variant selection”. This kind of selection in the context of diffusional transformations contrasts with displacive products where the interaction of transformation plasticity with an exte...

The solidification process in a weld pool has been shown to have a considerable influence upon the properties of the resultant weld. It influences the development of microstructure (Edvardsson et al., 1976), and determines the distribution of alloying elements, and hence the homogeneity of the weld. Previous work on the cooling behaviour of welds (Garland and Kirkwood, 1974; Svensson et al., 19...

The effects of the presence of the R-phase in a near-equiatomic NiTi alloy on the mechanical responses of an endodontic instrument were studied by using finite element analysis. The input data for the constitutive model in the simulation were obtained by tensile testing of three NiTi wires: superelastic austenite NiTi, austenite + R-phase NiTi, and fully R-phased NiTi. The wires were also chara...

The response of a strong bainitic–steel to tempering at high temperatures is investigated, because a softened state is sometimes necessary during the manufacture of engineering components, prior to the final heat–treatment which hardens the material. Thermodynamic calculations conducted to determine the maximum temperature at which the steel could be annealed without forming austenite were foun...

Ferromagnetic shape memory alloys are characterized by strong magneto-mechanical coupling occurring at the atomic scale causing large magnetically inducible strains at the macroscopic level. Employing combined atomic and magnetic force microscopy studies at variable temperature, we systematically explore the relation between the magnetic domain pattern and the underlying structure for as-deposi...