2 0 0 0 OA 鉄の転位強化に及ぼすNiの影響
- 著者
- 赤間 大地 土山 聡宏 高木 節雄
- 出版者
- 一般社団法人 日本鉄鋼協会
- 雑誌
- 鉄と鋼 (ISSN:00211575)
- 巻号頁・発行日
- vol.103, no.5, pp.230-235, 2017 (Released:2017-04-30)
- 参考文献数
- 21
- 被引用文献数
- 8
The dislocation strengthening was estimated by applying the dislocation theory for a Fe-18%Ni alloy which has a lath martensitic structure. The yield stress of highly dislocated metals is dependent on both the friction stress and the dislocation strengthening. Regarding the coefficient of dislocation strengthening, it is governed by the shear modulus of metals. Ni addition plays a role in increasing the friction stress but decreases the shear modulus. This means that the coefficient of dislocation strengthening is smaller in the Fe-18%Ni alloy than pure iron. It was confirmed that the yield stress, which was experimentally obtained in Fe-18%Ni alloy, is reasonably explained by the mechanism of dislocation strengthening, taking the effects of Ni into consideration. On the other hand, in the case of lath martensite with a dislocation density of 2×1015 /m2, it was also found that the effect of Ni addition does not appear on the yield stress because the increment of solid solution strengthening is cancelled out by the decrement of dislocation strengthening.
1 0 0 0 OA 微量炭素・窒素を添加したフェライト鋼のHall-Petch係数に及ぼす低温時効処理の影響
- 著者
- 荒木 理 藤井 浩平 赤間 大地 土山 聡宏 高木 節雄 大村 孝仁 高橋 淳
- 出版者
- 一般社団法人 日本鉄鋼協会
- 雑誌
- 鉄と鋼 (ISSN:00211575)
- 巻号頁・発行日
- vol.103, no.8, pp.491-497, 2017 (Released:2017-07-31)
- 参考文献数
- 28
- 被引用文献数
- 15
Effect of aging treatment at 373 K on Hall-Petch coefficient (ky) was investigated in consideration of the change in friction stress associated with carbide/nitride precipitation in ferritic steels containing 60 ppm carbon or nitrogen (C60 and N60). Tensile tests revealed that the ky was monotonously increased with increasing aging time in both steels, and also, C60 exhibited a larger ky value than that of N60 under the same aging time. As a result of 3DAP analysis and theoretical calculation for grain boundary segregation of carbon and nitrogen, the ky corresponded to the amount of carbon and nitrogen existing at grain boundary. There was no difference in the effect on ky increment between both elements. The larger ky in C60 under the same aging condition was due to the larger amount of segregated carbon compared with nitrogen.