Evaluation of the residual life and mechanical properties of steels with a heterophase structure

When a decision is made about prolongation of the safe service life of a critical facility above specified, measures are taken to diagnose its health and to determine its residual life. Evaluation of the residual life of critical facilities is a complex engineering problem; to solve it, one needs to have the results of a complex study of loading conditions and forms, mechanical characteristics, stress-strain state features, the presence of process defects and service-induced. The aim of this study is to create experimental methods for evaluating the residual life of critical facilities. To do this, we develop a model of degradation of the mechanical and physical properties of materials under a complex stress state and thermal action which correspond to the actual service conditions of a facility. In order to judge whether it is possible to prolong the service life of facilities, a full-scale investigation of their functional abilities is performed on the basis of studying the structure and physical-mechanical properties of a limited number of samples from one batch at the moment of investigation and a prediction is made with the use of the developed degradation model.