Tungsten strengthening 9-12% heat resistant steels have been developed for the application of the highly efficient ultra supercritical steam power plant because of the protection of natural environment and the preservation of fossil fuel. For these materials, creep test for a smooth specimen and charpy impact test have been performed to investigate basic mechanical properties. However, mechanical behaviors of creep crack growth and fracture have not yet been clarified. In this paper, using NF616 and TAF650, creep crack growth tests were performed and load line displacement laws under creep condition were derived and compared with those for creep ductile and brittle materials such as Cr-Mo-V steel and IN100 alloy. Furthermore, creep crack growth behavior was investigated and related to the metallurgical structure. From these studies, however, both of NF616 and TAF650 have initial ductility, load line displacement under creep condition was found to be restrained owing to the increase in the resistance to the creep deformation and crack growth due to structural strengthening mechanism. This characteristic is qualitatively similar as that for nickel based γ' precipitated superalloy (IN100).
|ジャーナル||Key Engineering Materials|
|出版ステータス||Published - 2000 1月 1|
|イベント||Proceedings of the 1999 8th International Conference on Creep and Fracture of Engineering Materials and Structures - Tsukuba, Jpn|
継続期間: 1999 11月 1 → 1999 11月 5
ASJC Scopus subject areas