Group leader, Cabot Corporation, Kokomo, Ind.
Pages: 15 Published: Jan 1979
The slow strain-rate technique (SSRT) was used to investigate the susceptibility of several nickel-base and cobalt-base alloys to environmental stress cracking. This technique was successful in revealing the stress corrosion cracking (SCC) tendency of a given alloy in a specific environment. Yet, the measurable quantities (percent elongation, percent reduction in area, load at failure, and the total time to failure) were not always consistent indicators of the SCC phenomenon nor of its severity. Metallographic examination allowed to quantify the susceptibility to SCC through the measurement of the average “secondary stress corrosion crack” depth. The effects of strain rate, solution temperature, and solution concentration were clearly established using the SSRT. However, the effect of cold work on the susceptibility to hydroxide stress cracking was inconclusive. Also, the SSRT was not able to distinguish the SCC phenomenon from that of a “stress assisted intergranular corrosion” occurring on sensitized material.
stress corrosion cracking, strain rate, nickel-base alloys, cobalt-base alloys, hydroxide stress cracking, chloride stress cracking, stress assisted intergranular corrosion
Paper ID: STP38121S