ステンレス鋼の極低温疲労組織と破面観察

概要

論文の詳細を見る
The measurements of fatigue crack growth characteristics at room and liquid nitrogen temperatures as well as the observations of microstructure and fracture surface topography of metastable 304Lwere carried out. The results obtaines were compared with those of stable austenitic stainless steels (310 and high Mn stainless steel). The effective stress range ratio of 304L steel at liquid nitrogen temperature was larger than that at room temperature or that of 310 steel. The blocks of α' martensite transformed from austenite via εmartensite were odserved in the close neighborhood of cracks in 304L steel,whereas no α' was found in the high Mn stainless steel. The fracture surface of 304L steel at liquid nitrogen temperature was smooth and flat. Based on these observations, the fatigue crack growth mechanisms in stainless steel at cryogenic temperatures were briefly discussed with emphasis on the crack closure.
1990-11-15