Tempering of low-carbon steels (less than about 0.3 wt.% C) may differ from the traditional precipitation sequence, which includes transition carbide precipitation, retained austenite decomposition and cementite precipitation. The main difference is the partial or total absence of transition carbides. In the present work, the effect of the carbon segregation on the mitigation of the precipitation of the latter is analyzed by combining multi-scale experimental investigations with a new precipitation model accounting for the carbon heterogeneities induced by the segregation. The full precipitation sequence is considered in order to study the impact of the segregation not only on the transition carbides, but also on the cementite which forms afterwards. The experimental work includes APT characterization of carbon segregation, HEXRD experiments to reveal precipitation kinetics, and TEM observations for carbide size measurements.

中文翻译：

---

低碳钢回火过程中碳偏析对过渡碳化物和渗碳体析出的影响：实验和建模

低碳钢（小于约0.3wt.%C）的回火可不同于传统的沉淀顺序，其包括过渡碳化物沉淀、残余奥氏体分解和渗碳体沉淀。主要区别是部分或完全不存在过渡碳化物。在目前的工作中，通过将多尺度实验研究与考虑碳偏析引起的碳异质性的新降水模型相结合，分析了碳偏析对后者降水缓解的影响。考虑完整的沉淀序列，以便研究偏析不仅对过渡碳化物而且对随后形成的渗碳体的影响。实验工作包括碳偏析的 APT 表征、揭示沉淀动力学的 HEXRD 实验以及碳化物尺寸测量的 TEM 观察。