種々の水環境下における高張力鋼の疲れき裂伝播挙動

概要

論文の詳細を見る
A parameter γ_<0.167Hz> which means the degree of the effect of water environment on fatigue crack growth rate has been evaluated using six kinds of 80∿120 kgf/mm^2 grade steels at the stress ratio of 0.10. γ_<0.167Hz>≡(da/dN)_<cor>/(da/dN)_<air>, where (da/dN)_<cor> is fatigue crack growth rate in each water environments at the frequency of 0.167 Hz and 30℃, and (da/dN)_<air> is that in air. Air-bubbling sea water, N_2 gas-bubbling pure water, air-bubbling pure water, air-bubbling 3% NaCl solution, and air-bubbling 3% NaCl solution with zinc sacrificial anode have been used as environments. The following results are mainly obtained. 1) When the maximum value of γ_<0.167Hz> is less than 3∿4, fracture surface almost shows transgranular. When the value is more than 3∿4, fracture surface shows intergranular. 2) The maximum value of γ_<0.167Hz> less than about 2 is not obtained for six kinds of high yield strength steels used and under the above five water environments. 3) Under the zinc sacrificial anode condition, the effect of corrosion control against fatigue crack growth is observed when ⊿K<30∿40 kgf/mm^<3/2>. However, the value of γ_<0.167Hz> is higher under the condition than under another water environments when ⊿K>30∿40kgf/mm^<3/2>. This fact can be explained by hydrogen arised due to cathodic reaction. 4) Under the zinc sacrificial anode condition, the maximum value of γ_<0.167Hz> are 5∿13 depending on prior austenitic grain sizes, which is explained by relating to cyclic plastic deformation size at the tip of crack.
1983-03-01

種々の水環境下における高張力鋼の疲れき裂伝播挙動

スポンサーリンク

概要

著者

関連論文

スポンサーリンク