Kistanov Andrey A, Rani Ekta, Singh Harishchandra, Fabritius Timo, Huttula Marko, Cao Wei
Nano and Molecular Systems Research Unit, University of Oulu, 90014 Oulu, Finland.
Centre for Advanced Steels Research, University of Oulu, 90014 Oulu, Finland.
Phys Chem Chem Phys. 2022 Jan 19;24(3):1456-1461. doi: 10.1039/d1cp05068k.
Non-metallic inclusions play a decisive role in the steel's performance. Therefore, their determination and control over their formation are crucial to engineer ultra-high-strength steel. Currently, bare experimental approaches are limited in the identification of non-metallic inclusions within microstructural phases of complex steel matrices. Herein, we performed a density functional theory study on the characteristics of different nitride inclusions as observed in spectro-microscopy studies. As per the simulations, TiN inclusions preferentially formed in the austenite matrix, while the ferrite matrix generally hosts BN inclusions. Furthermore, although the presence of both BN and TiN inclusions in the FeC matrix is possible, their formation is impeded because of the strong inclusion-carbon interactions. The observed regularity in the formation of nitride inclusions in different phases of steel was also confirmed by the comparison of simulated and experimental K-edge XAS spectrum of nitride inclusions. Our work shed the light on the formation of nitride inclusions in different steel matrices and facilitates their further experimental identification.
非金属夹杂物对钢的性能起着决定性作用。因此，对其进行测定并控制其形成对于制造超高强度钢至关重要。目前，单纯的实验方法在识别复杂钢基体微观结构相中的非金属夹杂物方面存在局限性。在此，我们对光谱显微镜研究中观察到的不同氮化物夹杂物的特性进行了密度泛函理论研究。根据模拟结果，TiN夹杂物优先在奥氏体基体中形成，而铁素体基体中通常存在BN夹杂物。此外，尽管在FeC基体中同时存在BN和TiN夹杂物是可能的，但由于夹杂物与碳之间的强烈相互作用，它们的形成受到阻碍。通过比较模拟和实验得到的氮化物夹杂物的K边X射线吸收谱，也证实了钢中不同相氮化物夹杂物形成的规律。我们的工作揭示了不同钢基体中氮化物夹杂物的形成情况，并有助于对其进行进一步的实验识别。
