【摘要】 研究了钛合金BT9和08X18H10T不锈钢在比例和非比例载荷下的低周疲劳特性,非比例载荷下钛合金BT9附加强化程度很小,08X18H10T不锈钢则产生了明显的附加强化,而二者的疲劳寿命均降低明显。采用透射电镜(TEM)对钛合金BT9及08X18H10T不锈钢的疲劳位错亚结构进行了对比分析,结果表明:非比例载荷下,钛合金BT9中局部高密度位错,以及08X18H10T不锈钢面塑性变形方式从平面状滑移向波纹状滑移转化,是其低周疲劳损伤程度加剧及寿命降低的主要原因。更多还原

【Abstract】 Multiaxial low cycle fatigue properties of titanium alloy BT9 and stainless steel 08X18H10T were investigated under proportional and non-proportional cycle loadings.Under non-proportional cycle loading,the additional hardening effect was obvious for 08X18H10T but not for BT9 and the fatigue life of both materials decreased dramatically.The TEM observation and analysis on the dislocation sub-structures of BT9 and 08X18H10T showed that the high dislocation density in some local areas of the dislocation sub-structures of BT9 and plastic deformation of 08X18H10 are major factors to aggravate LCF damage and shorten fatigue life.更多还原