Acceleration mechanism of Ti2O3 on TiN formation and δ-ferrite nucleation of ferritic stainless steel
Acceleration mechanism of Ti2O3 on TiN formation and δ-ferrite nucleation of ferritic stainless steel
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Ti2O3 对铁素体不锈钢 TiN 形成和 δ-铁素体形核的促进机制
DOI：
10.1016/j.jallcom.2022.165221
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发表时间：
2022
影响因子：
6.2
通讯作者：
Inoue Hiroshige
中科院分区：
文献类型：
--
作者：
Hou Yuyang;Cheng Guoguang;Kadoi Kota;Inoue Hiroshige
等轴凝固有助于铁素体不锈钢抗起脊缺陷。Ti_2O_3促进TiN的形成，使δ-铁素体形核，是近年来发现的一种促进等轴凝固的有效方法。然而，Ti 2 O3的加速机制尚不清楚，缺乏直接的成核证据。因此，在这项研究中，使用新设计的液滴实验保持初始凝固状态。通过位向关系校正的失准计算来理解形核现象。新发现的Ti_2O_3-TiN的形成源于钢凝固前形成的Ti-O-N颗粒。Ti-O-N颗粒中Ti 2 O3和TiN的顺序析出遵循{0001} Ti 2 O3// {111} TiN的取向关系，最终形成Ti 2 O3-TiN。随后，{001} δ-Fe // {001} TiN促进了Ti_2 O_3-TiN表面的δ-铁素体形核。液滴实验中保留的初生δ铁素体枝晶证实了上述机理。这些发现将扩大知识的氧化物加速形核，并可能有助于合适的成分设计等轴凝固。
Equiaxed solidification contributes to the ridging defect resistance of ferritic stainless steel. Ti2O3accelerating TiN formation to nucleate δ-ferrite was recently recognized as an effective method to promote equiaxed solidification. However, the acceleration mechanism of Ti2O3is still unclear, and there lacks direct nucleation evidence. Therefore, in this study, the initial solidification state was preserved using a newly designed droplet experiment. The orientation relationship calibrated disregistry calculation was carried out to understand the nucleation phenomena. It is novel to find that the formation of Ti2O3-TiN originates from the Ti-O-N particle, which forms before solidification of steel. The sequenced precipitation in the order of Ti2O3and TiN from the Ti-O-N particle follows the orientation relationship of {0001} Ti2O3 // {111} TiN and finally constitutes the Ti2O3-TiN. Afterward, the δ-ferrite nucleation will be promoted on the surface of the as-formed Ti2O3-TiN following {001} δ-Fe // {001} TiN. The primary δ-ferrite dendrite preserved in the droplet experiment affirmed the proposed mechanism. These findings will expand the knowledge of oxide accelerating nucleation and could contribute to suitable compositional design for equiaxed solidification.