A comprehensive analysis of the growth rate of stress corrosion cracks

Abstract

This paper is a synthesis of earlier results supplemented by new results to define a comprehensive analysis of the growth rate of stress corrosion cracking (SCC). Two mechanisms, anodic dissolution (AD) and hydrogen embrittlement (HE), have been considered to calculate the SCC growth rate of AA 7050-T6 for a surface-breaking crack with blunt tip in an aqueous environment. The relative contributions of each mechanism and their mutual interactions have been quantitatively assessed. Results show that AD provides critical conditions for HE, which explains in part a stepwise propagation of the crack. Finally, the total crack growth rate due to the combined effects of AD and HE has been determined, and numerical results have been compared with experimental data, and a calculation of the crack growth rate for a practical configuration has been presented.