S0404-1-4 環境水素の影響を受けた6061および7075アルミニウム合金の衝撃引張特性(衝撃問題の新たなる展開と応用(1))

Abstract

Impact tensile properties of T6-aged 6061 and 7075 aluminum alloys affected by atmospheric hydrogen were investigated. In order to introduce hydrogen from the atmosphere, the alloys were pre-deformed by a slow strain rate testing in a humid air atmosphere with a relative humidity of 90 %. For the pre-deformed specimens, the impact tensile tests were performed using split Hopkinson pressure bar method at an average strain rate of 5.0×10^2s^<-1> a set of the experiments, it was shown that the ductility in the impact test decreased when the T6-aged 7075 alloys were hydrogen charged. The hydrogen embrittlement sensitivity of the T6-aged 6061 alloys was lower than that of the T6-aged 7075 alloys. The decrease of the ductility due to hydrogen charging of the T6-aged 7075 alloys was closely related to the increase in the ratio of the intergranular fracture near the specimen surface.