Stress corrosion cracking in welded heat exchanger tube made of CuZn

A welded tube made of α brass suffered damage due to stress corrosion cracking. Previously, the tubes were brazed and lasted. The crack runs in the HAZ, which is the zone with the highest welding stresses. The matrix consists of (almost) pure α with fine precipitations. Some β-phase has formed in the weld. A partially recrystallized and segregated zone is present in the rim region under the paint.