The creep and anelastic recovery characteristics of a 10%Cr steel have been systematically investigated at 600 °C after subjecting the test material to various prior deformation histories. Constant-load forward creep tests on specimens, either with a tensile or compressive preloading history, indicated that over- and reverse-preloading respectively decreases and increases the early primary creep rate of the steel. The extent of decrease (or increase) in early primary creep rate is also found to be directly proportional to the magnitude of stress during prior loading while such a correlation is not clearly evident for material deformation in the secondary and tertiary stages. Specifically, the creep rate in the secondary and tertiary stages is lower for specimens with a compressive prior loading while the rupture time is notably shorter for tensile pre-loaded specimens. The observed effect of prior loading on the early primary creep behaviour can be explained by considering micro-backstress development (as a consequence of dislocation pile-up formation during the prior loading phase) that subsequently introduces a kinematic hardening effect to the material's viscoplastic response. The second set of experiments involve monitoring the anelastic recovery behaviour immediately after accumulation of a similar amount of time-dependent strain either under forward creep (load control mode) or stress relaxation (strain control mode) condition in completely unloaded 10%Cr steel specimens at 600 °C. Experimental observations indicate that the higher the stress magnitude during the prior loading phase, the greater and faster the anelastic recovery at zero stress. Further findings show the mode of prior deformation (creep or relaxation) to also not noticeably influence the subsequent anelastic recovery behaviour. The observed anelastic recovery characteristic can be mechanistically interpreted by consideration of the time-dependent material back-flow due to the relaxation of dislocation bows and pile-ups generated during the prior deformation.

在使测试材料经历各种先前的变形历史后，已在600°C下系统地研究了10％Cr钢的蠕变和无弹性恢复特性。在具有拉伸或压缩预紧力历史的试样上进行恒定载荷正向蠕变试验，结果表明，超载和反向预紧力分别降低和提高了钢的早期初蠕变率。还发现早期初级蠕变速率降低（或增加）的程度与先前加载过程中的应力大小成正比，而这种相关性对于第二级和第三级的材料变形而言并不明显。具体来说，事先压缩的样品在第二和第三阶段的蠕变速率较低，而拉伸的预加载样品的破裂时间则明显较短。可以通过考虑微背应力的发展（由于在先前加载阶段期间位错堆积形成而导致的结果）来解释先前加载对早期主要蠕变行为的影响，随后会在运动过程中对材料的粘塑性响应产生运动硬化效应。第二组实验包括在完全卸载的10％Cr钢试样中，在正向蠕变（载荷控制模式）或应力松弛（应变控制模式）条件下，在累积相似量的随时间变化的应变之后，立即监测无弹性恢复行为。 600℃。实验观察表明，在先前的加载阶段，应力大小越高，零应力下的弹性恢复越大且越快。进一步的发现表明，先前变形的方式（蠕变或松弛）也不会显着影响后续的非弹性恢复行为。可以通过考虑随时间变化的材料回流来机械地解释观察到的非弹性恢复特性，这归因于位错弓的松弛和在先变形期间产生的堆积。