High-Temperature Fatigue Crack Propagation Property of Mod. 9Cr-1Mo Steel in Vacuum and in Air.
Year: 1997
Type: article
Abstract: Mod 9Cr-1Mo steel is potential material for the steam generator in fast breeder reactors. One of the features of creep-fatigue life property of the steel is the significant life reduction in compressive hold tests. In order to study the possible reason for the life reduction in compressive hold tests, microcrack propagation behavior under high-temperature fatigue in vacuum and in air were periodically observed. Microcracks propagated in the direction normal to the stress axis in vacuum while they propagated in the maximum shear direction in air. It was found that the crack propagation rate in air was faster than that in vacuum until the crack grew to 1 mm length due to an oxidation effect which was insignificant for cracks larger than 1 mm. Acceleration of the crack propagation rate in the compressive hold test was considered to be caused by accumulation of tensile strain in the center of the specimen due to an imbalance in the strain distribution between the tension and compression sides.
DOI: 10.1299/kikaia.63.7
Authors: Takashi OGATA, Masato YAMAMOTO
Language: English
Subfield: Mechanics of Materials
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2317439740