Associate professorFaculty, Ryukoku University, Ohtsu,
Staff engineer, Chiyoda Corp., Yokohama,
Pages: 20 Published: Jan 1990
The holding-load and fractographic (HLF) test method has been proposed by the authors to measure the threshold stress intensity KIH or KIscc and the crack growth rate in a hydrogen or corrosive environment. In this paper, the HLF method was used to measure KIH for five different heats of ASME SA387 Grade 22, Class 2 steel, and the effect of the hydrogen, material, and loading conditions on KIH were examined. The diffusive behavior of hydrogen in the test materials and the modes of fracture due to hydrogen-assisted cracking (HAC) were also investigated. KIH, obtained by the HLF method, showed just a little dependence on the tensile strength and was considerably lower than the existing literature data for relatively low-strength steels. The fracture toughness KCH of one of the materials in the environment was measured by the HLF test and the modified JIc test. Although KIH was shown to be very low, KCH was nearly equal to KIc, the plane-strain fracture toughness in a neutral environment, and it was considered not to have been lowered by the hydrogen environment.
fractography, fracture toughness, threshold stress intensity, K, IH, K, Iscc, K, Ic, J, Ic, test, hydrogen-assisted cracking, crack growth rate, diffusion of hydrogen, mode of fracture, intergranular, quasi-cleavage
Paper ID: STP23535S