クリープ疲労条件下における粒界キャビティ発生の分布特性

概要

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Creep-fatigue damage at high-temperature on SUS 304 austenitic stainless steel is characterized by nucleation and growth of creep cavities on grain boundaries. We had carried out the continuous observation of the cavity growth under creep-fatigue condition and clarified its mechanisms. In this study, in order to clarify distribution properties of cavity nucleation under the creep-fatigue condition, creep-fatigue tests with CP waveform were conducted on SUS 304 stainless steel and the failure specimens were examined by scanning electron microscope. As a result, it was found that the cavitated grain boundaries exsisted almost normal to a stress axis regardless of tensile strain-rate and the volumetric density of damaged grain boundary increased monotonously with the inelastic strain range. The volumetric density of damaged grain boundary, whchi is expressed as a function of time-dependent strain, was proposed based on test results of CP waveform condition and the volumetric density under strain-hold waveform condition could be predicted with good accuracy.
一般社団法人日本機械学会の論文
1998-04-26