Abstract
An analysis is given of the modern outlook on the mechanism of cracking in high strength steel in the case of stress corrosion cracking (SCC). It is shown that numerous experimental data cannot be interpreted in terms of hydrogen embrittlement when it is considered as the only mechanism of crack growth. A phenomenon is described of multiple effects of cathodic polarization on the rate of crack growth in cracking of high strength steels. A new mechanism of SCC is suggested, whose main feature is found in that it not only allows for, but is in fact based upon the possibility of SCC of high strength steels by several mechanisms: local anodic dissolution, hydrogen embrittlement, and adsorption strength reduction. The mechanism entails alternation of rate-limiting processes, depending on various metallurgical and electrochemical factors, and on crack growth rate, which affect the kinetics of formation of barrier layers at the crack tip. A definition of critical growth rate is introduced, which is then investigated as function of a number of factors.
LITERATURE SURVEY OF STRESS-CORROSION CRACKING AND HYDROGEN EMBRITTLEMENT IN HIGH STRENGTH STEELS.
