EFFECT OF GRAIN SIZE ON COLLECTIVE DAMAGE OF SHORT CRACKS AND FATIGUE LIFE ESTIMATION FOR A STAINLESS STEEL |
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| Authors: | Hong Qiao Liu & Zheng |
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| Affiliation: | Laboratory for Non-linear Mechanics of Continuous Media (LNM), Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China |
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| Abstract: | In the short crack regime of the fatigue process, grain boundaries in steels are barriers against crack growth. In this paper, we use: (1) a method involving crack density; and (2) a method of dimensional analysis, to evaluate the effects of grain size and grain-boundary resistance on short crack behaviour and fatigue life. The results show that the fatigue life increases with a decrease in grain size and an enlargement in the obstacle effect of a grain boundary. An experimental investigation is consequently performed and four groups of stainless steel specimens are used with different grain sizes. The experimental measurements show the dependence of fatigue properties on grain size, which are in good agreement with the theoretical results. |
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| Keywords: | Short fatigue cracks Fatigue life Grain size effect Stainless steel Crack density Dimensional analysis |
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