3507 水素ステーション蓄圧器用SCM435鋼の低サイクル疲労特性におよぼす水素と周波数の影響(S20-2 水素チャージ材の強度特性,S20 材料強度特性に及ぼす水素の影響)
詳細
Low cycle fatigue tests on SCM435 steel tempered at 580℃ were carried out under the frequencies of 0.2, 2 and 20Hz with specimens containing a small artificial hole. The fatigue life of the hydrogen charged specimens decreased in comparison with the uncharged specimens. The acceleration of fatigue crack growth rate was observed at ΔK<40MPa√<minf=20Hz>, ΔK<60MPa√<minf=2Hz> and ΔK<100MPa√<minf=0.2Hz>. Facets were formed on the fracture surface of hydrogen charged specimens in the ΔK region where the crack growth rate was accelerated. Many slip bands were observed at the crack tip of the uncharged specimens. On the other hand, slip bands were not clear the hydrogen-charged specimens.
