SUS 316 鋼の高温低サイクル疲れ寿命におよぼす漸増平均ひずみの影響(高温の組織と強度)(<特集>耐熱鋼・耐熱合金)

概要

論文の詳細を見る
Fatigue tests were carried out on a Type 316 stainless steel at 600 and 700℃ in order to clarify the effect of creep deformation increasing gradually during fatigue tests on elevated-temperature, low-cycle fatigue life. Strain wave forms with or without rising mean strain were used for truncated wave form with a 10-min hold in tension only and triangular wave form. The strain rate of ramps were 40%/min. For a given total strain range, fatigue life of the truncated wave form is smaller than that of the triangular wave form. The difference between them obtained at 600℃ is larger than obtained at 700℃. Well-defined intergranular facets covered with small dimples were observed for specimens tested under truncated wave form at 600℃, but not at 700℃. These results could be explained by phenomenom of recovery process at 700℃, because of which stress applied grain boundaries might have decreased under truncated wave form. Rising mean strain per cycle under truncated wave form was creep strain, however no clear effect of the rising mean strain on low-cycle fatigue life was observed. Summation of the creep strain corresponding to relaxation stress and rising mean strain per cycle were almost constant for a given total strain range. It is considered that this is a reason why no effect of rising mean strain on fatigue life was observed.
社団法人日本鉄鋼協会の論文
1979-06-01