Magnetic Properties of Fe-M-O(M=Zr, Hf) Films with High Resistivity.

Characterization of Mechanical Properties for Ferritic Heat-Resisting Steels (12Cr–2W) with Different Creep-Fatigue Properties by Nano-Indentation

“…In other words, coarse blocks of specimens after the creepfatigue test near to the prior £ grain boundaries where pop-in behaviors occurred have a significantly low dislocation density, compared to the fine blocks far from the grain boundaries. Structure observations in the previous paper 6) reported that subgrains in coarse blocks grew to the same size as the block width. This suggests that the pinning effect of precipitate particles in the blocks was also low.…”

“…The surfaces of the specimens were polished with diamond (particle size: 1 µm), mirror-finished, and electropolished. 6,7) A nanoindentation tester is based on an atomic force microscope (AFM). 8) The XY scan range of the tester is 9 µm © 9 µm.…”

“…However, in a plate material that has prior £ grain size of 3050 µm, and shows transgranular fracture, almost no coarse subgrains localized near the grain boundaries were observed even after the creep-fatigue rupture. 7) These findings suggest the following two factors shorten the creep-fatigue lifetime of the pipe material. First, precipitates at the prior £ grain boundaries become coarse and the area fraction of the grain boundary precipitates increase due to the large prior £ grain size.…”

“…Moreover, the subgrains became coarse, and the coarse subgrains existed more in the neighborhood of the prior £ grain boundaries. 6) Because blocks in the neighborhood of the prior £ grain boundaries tend to become coarse, subgrains grew to the same size as the block width. However, in a plate material that has prior £ grain size of 3050 µm, and shows transgranular fracture, almost no coarse subgrains localized near the grain boundaries were observed even after the creep-fatigue rupture.…”