Papers by Keyword: Interstitial Atoms

Abstract: The effect of oxygen content on the stability of α′′ martensite phase of the Ti-20mol%Nb alloy was investigated by differential scanning calorimetry. The reverse martensitic transformation temperature increased with increasing oxygen content, and this means that α′′ martensite phase was stabilized by oxygen addition. The mechanism of α′′ martensite stabilization by oxygen atoms was discussed based on the changes in the lattice parameters of α′′ martensite.

Abstract: The problem undertaken in the present work concerns the kinetics of evolution of radiation induced damage under mechanical loads. Furthermore, coupling between the radiation induced nanodamage and the mechanically induced micro-damage is taken into account. The evolution of radiation induced damage is combined with the evolution of classical mechanically induced damage within the common framework of Continuum Damage Mechanics (CDM). Closed form analytical solutions for the problem of periodic irradiation combined with cyclic axial loads, corresponding to Rice & Tracey law was obtained.

Abstract: The proposed dislocation model describes the orientation dependence of the critical resolved shear stress (CRSS) and deformation mechanisms on the yield point in single crystals of austenitic stainless steel with nitrogen impurities. The model takes into account the following: the change of the interstitial atom position in the lattice from octahedral interstice to tetrahedral site owing to passage of a leading Shockley’s partial dislocation; the change in the separation width between two partial dislocation in external stress field; the relationship between the width of the extended dislocation and the elastic interaction of the extended dislocation with the impurity atoms.

Abstract: The motion of interstitial atoms (one of the point defects) in material is random under certain temperature. However, the diffusion of interstitial atoms has priority along some certain directions to the others, so it is necessary to reveal the phenomenon (the phenomenon also can be called anisotropic). In order to illustrate the anisotropic and reveal the magnitude of probability of the micro crack formation along crystal axes, some formulae derived from former literatures have been adopted, and the values of diffusion probability and diffusivity of interstitial atoms-Ti or Al along 〈110〉and〈100〉have been calculated. The conclusion that the diffusion of interstitial atoms along different crystal axis has different diffusivity is verified by the comparison of the results of calculations.

Abstract: The influence of the texture development in Ti-added (0.03, 0.05 and 0.07wt%) IF (Interstitial Free) steels on physical properties, especially ř -value was investigated. It was intended to determine the proper Ti content for the promotion of deep drawability as well as mechanical properties of IF steels. The precipitation behavior in the IF steels was clarified with the aid of computer simulation. The quantitative X-ray analysis on the texture development of IF steels was performed using pole figure and orientation distribution function measurement. For the IF steel with the composition of 0.025C, 0.070Mn, 0.002N and 0.007S, the optimum Ti content was found to be 0.05wt%.