論文
窒素または炭素を含有するLaves強化型フェライト系耐熱鋼のクリープ変形挙動と微細組織
キーワード:
ferritic heat-resistant steel,
high-nitrogen steel,
creep,
microstructure,
Laves phase,
dislocation density
2023 年 109 巻 3 号 p. 167-178
詳細
2023 年 109 巻 3 号 p. 167-178
The creep deformation behavior and microstructure of a N-containing steel expected to exhibit high creep strength and excellent oxidation resistance were investigated. Even for steel with a high W content, it was possible to form a martensitic microstructure by adding a sufficient amount of N. Comparison of the microstructures of the N-containing steel and a C-containing steel confirmed that the two steels have the same crystal orientation relationship. The N-containing steel precipitated with the Laves phase as a strengthening phase displayed a higher creep strength than conventional steel under relatively high stress. However, the superiority of the creep strength of the N-containing steel relative to the conventional steel decreased under low stress. The stress exponent of the N-containing steel was different from those of the C-containing steel and the conventional steel. This deference considered to be ascribed to the difference of variation behavior of dislocation density during creep deformation.
