in this investigation, continuous cooling transformations and microstructures have been studied in detail in a low carbon ti-nb bearing microalloyed steel by means of dilatometry, metallography and hardness measurements. the results indicate that when the cooling rate is greater than 1˚c/s, the dilatation curve is associated with a major dilatation at relatively low transformation temperatures,...

If the shape memory alloy is subjected to the subloop loading under the stress-controlled condition, creep and creep recovery can appear based on the martensitic transformation. In the design of shape memory alloy elements, these deformation properties are important since the deflection of shape memory alloy elements can change under constant stress. The conditions for the progress of the marte...

The depth of scientific understanding of martensitic transformations provides a strong foundation for the predictive design of materials exploiting artensitic phenomena. Recent theoretical advances supporting this capability include twoand three-dimensional applications of Landau–Ginzburg heory to martensitic nucleation, and important refinements of multiscale kinetic theory. Accurate control o...

Kinetic dependence of martensitic transformation and properties changes in Fe-24%Ni5%Mo alloys with different carbon content have been obtained. Internal friction method was used for the precise investigation of structural changes after austenization, during martensitic transformation at sub zero temperature and during the postheat. The influence: (i) of frequency of oscillations, (ii) rate of ...

Statistica1 thermodynamics of martensitic transformation is developed in the frame of the self-consistent field approximation. The accommodation mechanisms of the parent phase to the martensitic variant growth are described by the three order parameters. The latters reflect the concentration and the orientation of the martensitic phase and the dislocation density at the interphase boundaries. S...

The kinetics of martensitic transformation in austenitic Fe-Ni-Mo alloys depends on the carbon content. Analysis of carbon redistribution between f.c.c. solid solution and dislocation has been carried out with the help of internal friction (amplitude and temperature effects) study and stress relaxation tests. The martensitic transformation was proved by magnetic induction and thermal differenti...

Titanium-based shape memory alloys undergo a cubic to orthorhombic martensitic transformation (β to α’’ martensite). A new easy way operating as a reconstruction of the parent microstructure is used from electron backscattered diffraction. It is shown that the electron backscattered patterns of the martensitic microstructure can be directly indexed as the parent phase in order to obtain the cor...

cryogenic treatment can be used as a supplemental treatment that is performed on some tool steels between quenching and tempering as an effective method for decreasing retained austenite and increasing wear resistance. in this research, the effect of deep cryogenic treatment (dct) on dimensional stability and mechanical properties of 80crmo12 5 tool steel was investigated. the martensitic trans...

The relationship between the crack nucleation and stress-induced martensitic transformation in the retained massive austenites (RM’s) of austempered ductile irons (ADIs) was examined in detail by carrying out tensile tests and scanning electron microscope (SEM) observations for an ADI material. The SEM observations revealed that cracks were not nucleated in the peripheral regions of graphite no...

Shape memory materials are a class of smart materials able to convert heat into mechanical strain (or strain into heat) by virtue of a martensitic phase transformation. Some brittle materials such as intermetallics and ceramics exhibit a martensitic transformation but fail by cracking at low strains and after only a few applied strain cycles. Here we show that such failure can be suppressed in ...