Microstructure and property evolution of a powder-forged Fe-2.5Cu-C alloy during continuous cooling and subsequent aging were investigated to improve its mechanical properties. During continuous cooling, copper precipitates formed were consistent with the interphase mechanism when the cooling rate was less than 7 °C/s; however, the hardness of the specimen was always higher at faster cooling rates because finer grains and harder phases formed. During subsequent aging, copper precipitates formed and/or coarsened continuously while the hardness of the alloys was greatly influenced by the combined effects of the primary and secondary precipitates, as revealed by the theoretical calculations. In addition, the forming and evolving mechanisms of the copper precipitates at different stages were also discussed based on the experimental results. This study will provide guidance to the industry for achieving high performance in the powder-forged products by treatment manipulation.

中文翻译：

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粉末锻造Fe-2.5Cu-C合金连续冷却及随后时效过程中的铜析出行为

研究了粉末锻造的Fe-2.5Cu-C合金在连续冷却和随后时效过程中的组织和性能演变，以改善其机械性能。连续冷却过程中，冷却速率小于7°C / s时，形成的铜析出物与相间机理相符。但是，在较快的冷却速度下，试样的硬度始终较高，因为会形成更细的晶粒和更硬的相。如理论计算所揭示的，在随后的时效过程中，铜沉淀物连续形成和/或粗化，而合金的硬度在很大程度上受到初次和二次沉淀物的联合作用的影响。此外，还根据实验结果探讨了铜沉淀物在不同阶段的形成和演化机理。