Author(s)

M. Arai, T.Ogata & A. Nitta

Abstract

In order to clarify microcrack initiation and propagation mechanism, creep and creep-fatigue tests with tensile hold-time were conducted on SUS304 stainless steel, with large grain size produced by a particular heat treatment, by using a high-temperature fatigue machine combined with a SEM. Microstrain distribution in grains and around grain boundaries on the specimen surface during the tests were measured by analysing the distortion of micro grids. It was found that the deformation progressed with inhomogeneous microstrain distribution under creep- fatigue condition. Initiation of the microcrack mainly related to strain concentration in the grain around grain boundary. The microcrack also propagated under the inh

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