Back (Corrosion Damages)

CuAl8 solder on S235JR, liquid metal induced stress corrosion cracking

Chemical designationCuAl8 solder on S235JR
StateSolder connection

The microstructural pictures impressively show the diffusion of Cu into Fe.
Iron has a decreasing solubility of maximum 2.2 wt.% Cu at 850 °C. The Cu diffuses along the grain boundaries of the iron and embrittles them. In the crack, the Cu concentrates to approx. 90 %.