Characterization of heterogeneous–nano structure in austenitic stainless steel: crystal orientations and hardness distribution
Characterization of heterogeneous–nano structure in austenitic stainless steel: crystal orientations and hardness distribution
复制标题
奥氏体不锈钢异质纳米结构的表征：晶体取向和硬度分布
DOI：
10.1007/s10853-020-04643-1
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发表时间：
2020
影响因子：
4.5
通讯作者：
H. Miura
中科院分区：
文献类型：
--
作者：
N. Koga;Shinya Suzuki;Hua Jiang;C. Watanabe;Y. Aoyagi;M. Kobayashi;H. Miura
系统地研究了SUS 316LN奥氏体不锈钢冷轧态非均匀纳米组织的硬度分布。HN结构由被剪切带包围的孪晶畴组成，剪切带进一步嵌入到传统的低角度层状结构中。孪晶畴中{111}的孪晶面几乎平行于轧制方向（RD）。孪晶平均间距为20-40 nm。层片的纵向也几乎平行于RD，平均界面间距约为100 nm。剪切带内形成了平均尺寸约为100 nm的超细晶粒。利用透射菊池衍射技术观察的显微组织表明，与剪切带和片晶相比，孪晶畴内的取向差和晶粒平均取向差均较低，孪晶畴内孪晶界的取向差角仍保持在60°。另一方面，在剪切带内的晶粒间的取向差角是相当大的。冷轧过程中，剪切带内的强烈应变局部化将导致瞬时形成由大角度晶界包围的超细晶粒。这些结果表明，孪晶畴内的位错密度低于剪切带和片层晶粒内的位错密度。虽然孪晶域具有比剪切带和层状晶粒中的更小的边界间距，纳米压痕测试显示，硬度在组分纳米结构之间几乎是相同的。纳米结构中几乎相同的硬度归因于孪晶畴中的位错强化量低于剪切带和层状畴中的位错强化量。
Hardness distribution in the heterogeneous–nano (HN) structure developed in a heavily cold-rolled SUS316LN austenitic stainless steel was systematically investigated. The HN structure consisted of twin domains surrounded by shear bands, which were further embedded in the conventional low-angle lamellae. The twining planes of {111} in the twin domains were nearly parallel to the rolling direction (RD). The average twin spacing was 20–40 nm. The longitudinal direction of the lamellae was also nearly parallel to the RD, and the average interboundary spacing was about 100 nm. Rather shortened ultra-fine grains with an average size of 100 nm were well developed within the shear bands. Microstructural observations using the transmission Kikuchi diffraction technique revealed that both of the disorientation and the value of the kernel average misorientation in the twin domains were relatively low compared to those in the shear bands and lamellar grains, and the misorientation angle of twin boundaries within the twin domain still remained 60°. On the other hand, the misorientation angles among grains within the shear bands were considerably high. The intense strain localization within the shear bands during cold rolling would result in the instant formation of ultra-fine grains surrounded by high-angle boundaries. These results suggested that dislocation density within twin domains was lower than that of the shear bands and lamellar grains. Although the twin domains possess a smaller interboundary spacing than that in the shear bands and lamellar grains, nanoindentation tests revealed that hardnesses were almost identical among the component nanostructures. The nearly identical hardness among the component nanostructures would be ascribed to a lower amount of dislocation strengthening in the twin domains than that in the shear bands and lamellae.
通过大应变加工开发多功能合金
DOI：
--
发表时间：
2017
期刊：
影响因子：
--
作者：
K. Edalati;H. Emami;Y. Ikeda;H. Iwaoka;Isao Tanaka;E. Akiba;Z. Horita;Zenji Horita;堀田善治
通讯作者：
堀田善治