Effect of Microstructure and Microchemistry on the SCC Behavior of Archival and Modern Pipeline Steels in a High pH Environment

Abstract

Abstract Six different heats were chosen from an archival data base of X52 pipeline steel using a statistical test design to evaluate the microstructure/microchemistry effects of S, P, and C. Additionally, three heats (X65, X70, X80) of a modern steel were added to the test matrix. Crack growth rates were carried out using compact tension specimens in the carbonate/bicarbonate environment at 75°C and under potential control to evaluate the stage II crack growth rates and the Klscc. In general, the microstructure/microchemistry had a small effect on the SCC behavior. However, the three modern steels had a significantly lower Klscc compared to the X52 steels.