In contrast to high pH SCC, the crack propagation through pipe wall thickness is of a transgranular nature. Near-neutral pH SCC cracking typically occurs in association with pits and general corrosion, as it occurs under freely corroding conditions, i.e. As for high pH SCC, the surface cracks generally form colonies in the axial direction of the pipe.
Near-neutral pH SCC also occurs on external pipe surfaces under areas of coating disbondment but where CP is fully shielded. Near Neutral pH Stress Corrosion Cracking
