Abstract: Grain boundary is the main block of propagation of microstructural short fatigue crack,and fatigue limit in nature is the minimum stress at which fatigue ctack may initiate but cannot propagate through the grain boundary.In this paper,a new method for the determination of fatigue limit of material using the non-propagation behaviors of crack is presented based on the analysis of propagation condition of microstructural short fatigue crack,which consider the effect of grain orientation on efficient driver of crack propagationand the critical barrier of grain boundary.It is shown that the method presented in this paper is practical and reasonable by comparing with others.

Key words: short fatigue crack； propagation condition； fatigue limit；