Manager, Fracture Mechanics, Structural Behavior of Materials Department, Westinghouse Research and Development Center, Pittsburgh, Pa.
Pages: 15 Published: Jan 1980
A preliminary investigation was conducted to evaluate the influence of both tension and compression prestressing (in air) on the subsequent stress-corrosion crack initiation behavior of two high-strength AISI type 4340 steels, 1240-MPa (180-ksi) and 1480-MPa (215-ksi) yield strength. Crack initiation testing was conducted with edge-notched, round tensile specimens subjected to a hydrogen sulfide (H2S) gas environment. Test results are expressed in terms of the critical combination of maximum elastically calculated notch stress and square root of the notch radius required to induce stress-corrosion cracking. Results show that prestressing can have a significant effect on subsequent stress-corrosion behavior. In general, tension prestressing increased the resistance to stress-corrosion crack initiation and compressive prestressing decreased the resistance. The susceptibility to stress-corrosion crack initiation was increased by as much as a factor of 4 to 1 as the result of compressive prestressing.
initiation, stresses, corrosion, fractures (materials), notch, steels, crack propagation, corrosion
Paper ID: STP36966S