Abstract Quenching and partitioning (Q&P) steels possess high strength and good ductility because of the transformation of metastable austenite to martensite, which is referred to transformation-induced plasticity (TRIP) effect. In literature, TRIP effect generally results in an enhancement of work hardening rate during tensile test. Nevertheless, the present work observes an abnormal TRIP effect in a 1500 MPa Q&P steel. Although a considerable amount of retained austenite transformed to martensite during the tensile test at a strain rate of 1000 s − 1, no obvious enhancement of work hardening rate was observed. To explore the underlying mechanisms for such an abnormal TRIP effect, the evolution of dislocation density and martensitic transformation were characterized by synchrotron X-ray diffraction and electron microscopy. Comparing the quasi-static and high-strain-rate results, it is found that the dislocation density in the martensite matrix is suppressed at 1000 s − 1, resulting in a lower work hardening. Furthermore, the transformed martensite deforms plastically at 1000 s − 1. Without the composite-like deformation behavior (elastically in hard transformed martensite and plastically in soft martensite matrix), the corresponding work hardening is reduced.

中文翻译：

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高应变速率下淬火隔板钢加工硬化行为的异常TRIP效应

摘要 淬火和分配(Q&P)钢由于亚稳态奥氏体向马氏体转变，称为相变诱导塑性(TRIP)效应，具有高强度和良好的延展性。在文献中，TRIP 效应通常会导致拉伸试验期间加工硬化率的提高。然而，目前的工作在 1500 MPa Q&P 钢中观察到异常 TRIP 效应。尽管在应变速率为 1000 s - 1 的拉伸试验期间有相当数量的残余奥氏体转变为马氏体，但没有观察到加工硬化速率的明显提高。为了探索这种异常 TRIP 效应的潜在机制，位错密度和马氏体转变的演变通过同步加速器 X 射线衍射和电子显微镜进行了表征。比较准静态和高应变率结果，发现马氏体基体中的位错密度在 1000 s - 1 时被抑制，导致较低的加工硬化。此外，转变马氏体在 1000 s - 1 时发生塑性变形。如果没有类似复合材料的变形行为（在硬转变马氏体中弹性变形，在软马氏体基体中塑性变形），相应的加工硬化就会减少。