Shinohara Yuri, Akabane Satomu, Inamura Tomonari
Laboratory for Materials and Structures, Tokyo Institute of Technology, 4259-J3-22, Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
Laboratory for Future Interdisciplinary Research of Science and Technology, Tokyo Institute of Technology, 4259-J3-22, Nagatsuta, Midori-ku, Yokohama, 226-8503, Japan.
Sci Rep. 2021 Jul 22;11(1):14957. doi: 10.1038/s41598-021-93514-z.
Herein, variant-pairing tendencies of lenticular martensite in an Fe-30Ni-0.3C (wt%) alloy are analyzed based on rank-1 connection at martensite/martensite junction planes (JPs) to facilitate the understanding of martensite microstructure. The degree of incompatibility (θ) at the JPs successfully explained their observed frequency; in the actual microstructure, variant pairs with a small θ form preferentially. The experimentally obtained JPs were consistent with theoretical ones. To the best of our knowledge, this is the first study to confirm the validity of variant-pair crystallography in steel based on rank-1 connection, both theoretically and experimentally. Diamond, composite-spear, and composite-kink clusters are considered. The cumulative θ at the JPs can suppress diamond cluster formation because it exceeds the θ of a single variant pair, and the diamond cluster is not observed experimentally. However, θ at the JPs cancel out in composite-spear (CS) and composite-kink (CK) clusters, but CK clusters are rarely observed experimentally, while a few CS clusters are observed. This demonstrates the analytical limitations of 2D approaches used to evaluate the frequency of variant pairs and clusters. These two variant clusters have a narrow window of 2D observation because the orientation relationships between JPs and intersection lines between two habit planes affect the areas of JPs.
在此，基于马氏体/马氏体界面平面（JPs）处的一级连接，分析了Fe-30Ni-0.3C（重量百分比）合金中透镜状马氏体的变体配对倾向，以促进对马氏体微观结构的理解。JPs处的不相容度（θ）成功解释了它们的观察频率；在实际微观结构中，具有小θ的变体对优先形成。实验获得的JPs与理论结果一致。据我们所知，这是第一项从理论和实验两方面证实基于一级连接的钢中变体对晶体学有效性的研究。考虑了菱形、复合矛状和复合扭折簇。JPs处的累积θ会抑制菱形簇的形成，因为它超过了单个变体对的θ，并且在实验中未观察到菱形簇。然而，JPs处的θ在复合矛状（CS）和复合扭折（CK）簇中相互抵消，但在实验中很少观察到CK簇，而观察到了一些CS簇。这证明了用于评估变体对和簇频率的二维方法的分析局限性。这两种变体簇具有狭窄的二维观察窗口，因为JPs与两个惯习面之间的交线之间的取向关系会影响JPs的面积。
