【摘要】 在恒△Ｋ控制条件下研究了ＭＩＳＩ３２１不锈钢在空气中不同过载比下的单周过载疲劳裂纹扩展延迟效应结果表明：过载比越大，延迟效应越显著，延迟效应作用距离远大于过载塑性区尺寸．讨论了裂纹过载延迟效应机理，认为ＡＩＳＩ３２１不锈钢过载后的疲劳裂纹扩展延迟行为主要由塑性诱发裂纹闭合引起，并对其进行了定量描述．更多还原

【Abstract】 The effect of single overload on fatigue crack growth rate for AISI 321 stainless steel hasbeen investigated under constant △K control and the retardation of crack growth was compared underdifferent overloading ratios. The results showed that the overload was followed higher crack growth ratezone at a short distance, a rate decreasing zone and a rate resuming zone. Higher overloading accompaniedhigher retardation effect. Under all overloading ratios, the retardation distance was much longer than thecalculated overloading plastic zone size at the crack tip. It was suggested that the plasticity induced crackclosure effect was mainly responsible for fatigUe crack growth retardation following overload for AISI 321stainless steel. A quantitative description was made for retardation effect.更多还原