Corrosion-Mechanical Fatigue: The Problems of Forecasting. Part 4. Assessment of Corrosion-Mechanical Fatigue Curve Parameters as Well as Durability of Materials

Corrosion is one of the main electrochemical processes that damage metal materials. The combination of cyclic stresses and a corrosive environment causes wear-fatigue damage, called corrosion-mechanical fatigue. The paper investigates the problem of predicting this type of wear-fatigue damage, which occurs in almost all branches of technology, especially in the chemical, oil, metallurgical industries, transport. The work consists of several parts. In the first part a technique for estimating the fatigue limit in a given corrosive environment (direct effect) is developed. The second part analyzes the reverse effect, i.e. the effect of acting stresses on the corrosion rate of metals and alloys, and proposes a method for predicting corrosion-erosion damage with the reverse effect based on the energy criterion. The third part discusses the mechanisms of corrosion-mechanical fatigue with direct and reverse effects. The fourth part considers the methodology of accelerated computational and experimental evaluation of the parameters of the power equation of the corrosion-mechanical fatigue and durability curve based on established correlation relationships. A diagram of the relative position of the curves of mechanical and corrosion-mechanical fatigue of the environment is given with a description of characteristic sections and points. The current tasks of further research are formulated.