Stress Corrosion Behavior of High Strength Steels

Abstract

Abstract The effect of stress and environment on the susceptibility to failure of HY-80, HY-130(T), 12Ni maraging, and 18Ni maraging steels has been evaluated by using both pre-notched and smooth specimens. Tests were conducted in sodium chloride solution, artificial sea water, and natural sea water, both with and without cathodic charging. Data are presented which show that the apparent susceptibility to failure is dependent on the test method used. Thus, in natural sea water, the most severe environment, notched specimens often showed failure, whereas, specimens of the same material tested in the unnotched condition did not fail. HY-80 steel was resistant to failure in all environments tested. HY-130(T) steel showed a slight reduction in load-carrying ability during cathodic charging, although the applied stress required for failure remained very high. Both 12Ni and 18Ni maraging steels failed as notched specimens in all test environments at applied stresses below the yield strength. In contrast, however, no failures were observed during the test period when these materials were tested as U-bend specimens in natural sea water.