Influence Of Microstructure On The Mechanical Behaviour Of Steel In Extreme Environment

In this study, the problem of brittle fracture of structures at low temperature conditions is connected to damage accumulation and ductile-brittle transition in metals. The data for energy equipment failure and locomotive tire contact impact fatigue are presented. The results of experimental testing show that the impact toughness drops at low temperature. The internal friction method was applied to revealing the mechanism of dislocation microstructure changes during the low-temperature ductile-brittle transition. It is possible to prevent the transition by severe deformation to change the steel microstructure which is quantitatively described by multifractal analysis. The proposed mechanism and revealing relationships would be used for theoretical and numerical modelling of damage accumulation and fracture in materials.