Model to Predict the Crack Growth Curves under the Influence of Creep and Corrosive Environment Simultaneously

In this paper the crack growth process of the parts subjected to hot fluids has been studied. The fluid high temperature activates the creep process. In addition the effect of the fluid corrosion as an important factor in the crack growth has been considered. The effective factors are divided into two groups of developing factors and resisting factors. For calculation of the developing forces, the inherited mechanical model has been used and after deriving the creep function, the amount of these forces has been determined in two stages of crack concealment and crack growth. The resisting force has been calculated using Rabotnov method of accumulated small fractures in the crack region. The effect of corrosive environment has been considered in the calculations using penetration function and the fluid standard density variations. For solving the resulted equations, programming in the MATLAB software has been used. Then the effects of the crack initial length, the applied stress and the fluid corrosiveness have been investigated on the crack growth curve.