Susceptibility of Iron-Rich Fe-Al Alloys to Embrittlement by Hydrogen and Water

Abstract

AbstractIron-rich Fe-Al alloys have been tensile tested in moist air and dry oxygen at a strain rate of 3.3×10−4 s−1. Moist air did not cause embrittlement until the composition reached 18-20% Al. Alloys with lower aluminum contents were embrittled when tested in hydrogen gas. The environmental sensitivity of these alloys was further investigated by examining the effects of strain rate on the ductility. For the most part, no significant strain rate effects were observed in the low aluminum alloys; strain rates of up to 3.3×10−1 s−1 were not fast enough to prevent embrittlement. In contrast, the ductility of Fe-35 at.% Al did increase with increasing strain rate in air and hydrogen; at a strain rate of 3.3×10−1 s−1 the elongations approached that of vacuum.