中文摘要：

研究了直接时效和形变时效对Fe-13．53Mn-4．86Si-8．16Cr-3．82Ni-0．16C合金第二相析出、马氏体相变和形状记忆效应的影响．SEM和XRD分析表明，时效后有大量Cr23C6第二相析出，但直接时效析出的Cr23Ca无方向性，而形变时效后Cr23C6呈方向性析出．相同时效时间下，形变时效析出的Cr23C6数量显著增多，且尺寸减小．两种时效均都能显著提高合金的形状记忆效应，且都存在一个最佳的时效时间．形变时效后的形状记忆效应达到82％，显著高于直接时效的记忆效应（43％）．通过控制第二相方向性析出，可制备出不需训练的高形变回复能力的铁基形状记忆合金．

英文摘要：

To develop Fe-based shape memory alloys with high recovery strain free of training, the effects of direct ageing and strain ageing on the precipitation of the second phases, the martensite transformation and the shape memory effect of an Fe-13.53Mn-4.86Si-8.16Cr-3.82Ni-0.16C alloy were investigated. The SEM and XRD showed that after ageing lots of 6r23C6 precipitated, while the precipitates after strain ageing are directional precipitation. At the same aging time, the amount of second phase through strain ageing is much more than that through the direct ageing, and the size of the former is smaller than that of the latter. The shape memory effect can be remarkably improved through both the strain ageing and ageing at the optimal aging time, but the shape memory effect of the former （82%） is much better than that of the latter （43%） at the same aging time. The Fe-based shape memory alloys with high revovery strain free of training can be fabricated through controlling the precipitated direction of the second phases.