open access

https://hdl.handle.net/2115/75460

Effect of Microstructural Change on Creep Rupture during Creep Deformation in 18Cr-9Ni-3Cu-Nb-N Steel

日本語

Schmid factor

2008-08-01

日本鉄鋼協会

鉄と鋼

94(8)

299-304

18Cr–9Ni–3Cu–Nb–N steel has the highest creep strength in the austenitic heat-resistant steels. It is expected as the component of the future thermal power plants. In order to clarify the mechanism of creep strengthening and creep rupture for the 18Cr–9Ni–3Cu–Nb–N steel, the creep test and the microstructural observations using electron microscopy were carried out. Seamless pipe was used as the sample because the initial microstructure for the sample conformed to the one for steels in the plants. From the TEM observation, fine NbX and Cu particles were formed in the austenite grains. The pinning effect by these particles is effective for the creep strengthening. In the regard to the microstructural change during the creep deformation, the crystal orientation rotations were observed using SEM-OIM. In the crystal grains rotated during the creep deformation, ‹001› or ‹111› was oriented to the tensile direction. Many boundaries were cracked due to these crystal rotations. This means that the creep rupture is occurred by the difference of the plastic deformation behavior between the grains oriented ‹001› to the tensile direction and the grains oriented ‹111› to it.

学術雑誌論文

Version of Record

著作権は日本鉄鋼協会にある

0021-1575

1883-2954

AN00151251