Abstract Primary creep regeneration (PCR) is an important phenomenon observed for some alloys loaded at high-temperature and under stress varying loading conditions. For example, for a specimen deforming in the secondary creep regime, a stress reversal might result in an enhanced creep rate upon reloading due to full/partial re-activation of the primary creep stage (i.e. primary creep regeneration). The extent of PCR activation is expected to be dependent on different loading parameters (e.g. magnitude and duration of reverse loading) and the characteristics of the loaded alloy. In this study, a comprehensive testing program was designed and conducted to investigate the PCR behaviour of an advanced 10%Cr martensitic steel at 600 °C. The experimental observations characterized the influence of different loading parameters on the extent of PCR activation. It was found that the inelastic strain accumulation during reverse loading periods is the most important parameter governing the extent of PCR activation after stress transients. Furthermore, the gathered experimental data was analysed to understand the effect of different loading parameters on anelastic recovery behaviour of the steel. It was shown that a larger amount of strain recovers after unloading for tests with higher forward stress magnitudes and/or larger amounts of pre-accumulated inelastic strain.

中文翻译：

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高铬马氏体钢在应力变化蠕变载荷条件下的蠕变行为：初级蠕变再生 (PCR)

摘要 一次蠕变再生（PCR）是一些合金在高温和应力变化加载条件下观察到的重要现象。例如，对于在二次蠕变状态下变形的试样，由于初级蠕变阶段的完全/部分重新激活（即初级蠕变再生），应力反转可能导致重新加载时蠕变速率增加。PCR 激活的程度预计取决于不同的加载参数（例如反向加载的幅度和持续时间）和加载合金的特性。在本研究中，设计并实施了一个综合测试程序，以研究高级 10% Cr 马氏体钢在 600 °C 下的 PCR 行为。实验观察表征了不同加载参数对 PCR 激活程度的影响。发现反向加载期间的非弹性应变积累是控制应力瞬变后 PCR 激活程度的最重要参数。此外，对收集到的实验数据进行了分析，以了解不同加载参数对钢的弹性恢复行为的影响。结果表明，对于具有更高前向应力大小和/或大量预累积非弹性应变的测试，卸载后会恢复更大量的应变。分析收集的实验数据以了解不同加载参数对钢的弹性恢复行为的影响。结果表明，对于具有更高前向应力大小和/或大量预累积非弹性应变的测试，卸载后会恢复更大量的应变。分析收集的实验数据以了解不同加载参数对钢的弹性恢复行为的影响。结果表明，对于具有更高前向应力大小和/或大量预累积非弹性应变的测试，卸载后会恢复更大量的应变。