Effect of Structural Heterogeneity of 17Mn1Si Steel on the Temperature Dependence of Impact Deformation and Fracture

Abstract

Abstract:The paper deals with a theoretical and experimental study of the relationship between the microstructural parameters, mechanical properties, and impact deformation and fracture of steels using the example of 17Mn1Si pipe steel. A model for the behavior of a polycrystalline grain conglomerate under impact loading at different temperatures was proposed within a cellular automata framework. It was shown that the intensity of dissipation processes explicitly depends on temperature and these processes play an important role in stress relaxation at the boundaries of structural elements. The Experimental study reveals the relationship between pendulum impact test temperature and the deformation/fracture energy of the steel. The impact toughness was shown to decrease almost linearly with the decreasing test temperature, which agrees with the fractographic analysis data confirming the increase in the fraction of brittle fracture in this case. It was shown with the aid of the proposed model and numerical simulations that the use of the excitable cellular automata method and an explicit account of test temperature through the possibility of energy release at internal interfaces help to explain the experimentally observed features of impact failure at different temperatures.

Impact of Dynamic Non-Equilibrium Processes on Fracture Mechanisms of High-Strength Titanium Alloy VT23

“…For the first time results were obtained that show the effect of DNP on changes in the fractographic features of the fracture surface of specimens from the titanium alloy. This makes it possible to predict changes in the mechanical properties of titanium alloys modified by the impact-oscillatory loading using the results of fractographic analysis [39,40].…”

Increasing Low-Temperature Toughness of 09Mn2Si Steel through Lamellar Structuring by Helical Rolling

“…In the previous paper [51], the authors-within the framework of the excitable cellular automata method [52][53][54]-implemented a model for the numerical description of the process of material fatigue under cyclic loading. This model used Mott's theory [55], which postulated the dominance of kinetic (thermal fluctuation) processes when considering the dynamics of sliding of crystallite planes.…”

“…Calculation of the material torsion angle enabled to quantify the induced change in density. For this purpose, the authors applied the approximation of the rod torsion model, considered in detail in [53,54]. Thus, χ, being the reciprocal of the density of dislocations, could be calculated proceeding from the local moment of forces by the formula:…”

“…Zhurkov) and the large-scale one (analyzed using the physical mesomechanic postulates), including the mesoscopic consideration of the deformation processes in Motts theory. The method explicitly took into account the energy dissipation during the nucleation of defect structures in accordance with the relation [54]…”

Morphological Characteristics of Dimples of Ductile Fracture of VT23M Titanium Alloy and Identification of Dimples on Fractograms of Different Scale

“…It is known that the processes of structural damage are depicted on the stress–strain diagram causing its nonlinearity, whereas fracture can be considered as the final stage of deformation that goes from the micro- and meso- levels to the macrolevel [11]. These physical–mechanical links between the levels of deformation and fracture are particularly important when analyzing the causes of unpredictable fracture of structures and evaluating their degradation mechanisms using fractographic analysis.…”