Expanded member comprising cu-al-mn alloy material and exhibiting superior anti-stress corrosion properties, and use therefor

Provided are: an expanded member of a Cu-Al-Mn alloy material that has a recrystallized structure substantially comprising a β-single phase and in which the frequency of occurrence of corresponding grain boundaries having an Σ value of 3 or less is in the range of 35-75%; and a use for the expanded member.