Research Of Hydrogen Induced Cracking And Stress-Corrosion Cracking In An Aluminum-Alloy

Abstract For a high strength aluminum alloy, the dynamic processes of nucleation and propagation of hydrogen induced delayed cracking of a charged and modified WOL specimen were followed metallographically. The results showed that the size of the plastic zone in front of the crack enlarged continuously with time, i.e., a hydrogen induced delayed plasticity was observed. Hydrogen induced delayed cracking then nucleated in the grain boundary or at inclusions when hydrogen induced delayed plasticity developed to a certain extent. Under the conditions of stress corrosion in high purity water and a 3.5% NaCl aqueous solution, stress corrosion cracking nucleated and propogated after the delayed plastic deformation had developed to a critical condition. The effects of the test temperature, polarization voltage, and chloride ion on KISCC and da/dt in high purity water were investigated. The results were identical with the effects of the aforesaid factors on the amount of hydrogen evolution of the specimens immers...