Stress-Corrosion Cracking of Metallic Materials. Part III. Hydrogen Entry and Embrittlement in Steel.

摘要

The chemical environment and metallurgical structure play important roles in the entry of hydrogen into iron and steel. In particular, the effect of compounds of sulfur, arsenic, phosphorus, selenium, and other elements, generally called 'cathodic poisoners,' is considered. The role of pH, electrochemical potential, stress, and temperature on the hydrogen entry kinetics is also considered. Metallurgical factors that influence the hydrogen entry and permeation rates include the alloy composition (substitutional and interstitial atoms), annealing and tempering (temperature, time), grain size, and the microstructure (form and distribution of carbides, etc.). The literature regarding the stress corrosion cracking of high-strength steel is reviewed. Studies of slow crack growth in gaseous environments are reviewed, with a comparison of crack growth behavior in both gaseous and aqueous media.