Allain Sébastien Y P, Aoued Samy, Quintin-Poulon Angéline, Gouné Mohamed, Danoix Frédéric, Hell Jean-Christophe, Bouzat Magali, Soler Michel, Geandier Guillaume
Institut Jean Lamour, UMR CNRS-Université de Lorraine 7198, 54000 Nancy, France.
Institut de Chimie de la Matière Condensée de Bordeaux, UPR CNRS 9048, 33608 Pessac, France.
Materials (Basel). 2018 Jun 26;11(7):1087. doi: 10.3390/ma11071087.
Quenching and Partitioning (Q&P) steels are promising candidates for automotive applications because of their lightweight potential. Their properties depend on carbon enrichment in austenite which, in turn, is strongly influenced by carbide precipitation in martensite during quenching and partitioning treatment. In this paper, by coupling in situ High Energy X-Ray Diffraction (HEXRD) experiments and Transmission Electron Microscopy (TEM), we give some clarification regarding the precipitation process of iron carbides in martensite throughout the Q&P process. For the first time, precipitation kinetics was followed in real time. It was shown that precipitation starts during the reheating sequence for the steel studied. Surprisingly, the precipitated fraction remains stable all along the partitioning step at 400 °C. Furthermore, the analyses enable the conclusion that the iron carbides are most probably eta carbides. The presence of cementite was ruled out, while the presence of several epsilon carbides cannot be strictly excluded.
淬火配分（Q&P）钢因其具有轻量化潜力，是汽车应用领域颇具前景的候选材料。它们的性能取决于奥氏体中的碳富集，而这又在很大程度上受到淬火配分处理过程中马氏体中碳化物析出的影响。在本文中，通过结合原位高能X射线衍射（HEXRD）实验和透射电子显微镜（TEM），我们对整个Q&P过程中马氏体中铁碳化物的析出过程给出了一些阐释。首次实时跟踪了析出动力学。结果表明，在所研究的钢种中，析出在再加热阶段就已开始。令人惊讶的是，在400℃的配分步骤中，析出分数始终保持稳定。此外，分析得出的结论是，铁碳化物很可能是η碳化物。排除了渗碳体的存在，而几种ε碳化物的存在不能被完全排除。
