CuZn39Pb2 | CW612N Stress corrosion cracking in brass

The brass screw connection of the flexible hose on a kitchen tap broke off.

The predominantly transcrystalline brittle fracture runs preferentially through the less noble beta phase. The many small side cracks indicate stress corrosion cracking (SCC). The hardness of 163 HV0.5 is clearly too high and makes the brass susceptible to stress corrosion cracking. A small dezincification attack under a locally perforated nickel layer (Fig. 10) has nothing to do with the damage.