アルミニウム合金の腐食疲労および長期間腐食後の疲労強度について

溶接構造用アルミニウム合金の疲労強度の研究 第4報

抄録

This report relates to corrosion-fatigue tests of 12 sorts of Al-Zn-Mg alloys in 3% aq. solution of NaCl and the effects of prior-corrosion in the atmosphere (atmospheric corrosion), in the service water (running), and in 3% aq. solution of NaCl for 2 years on fatigue strengths of 12 sorts of aluminum alloys.
The fatigue properties were examined with Ono's type rotating-beam fatigue tester, and the fatigue strengths were determined in 10⁷ cycles.
The corrosion-fatigue strengths of Al-Zn-Mg alloys were 5-6.8kg/mm², and almost no effects of heat treatment on the corrosion-fatigue strengths were observed.
The fatigue strengths of prior-corroded specimens had a tendency to decrease in the following order: atmospheric corrosion>3% aq. solution of NaCl>service water.
However, for some materials, the value in NaCl solution was higher than that of atmospheric corrosion.
Most of the reduction in fatigue strengths due to corrosion appeared during one year in the beginning. The average reduction factor of fatigue strength in atmospheric corrosion was 28%.