A desuperheater diffuser nozzle in the steam supply line failed within nine months of service in an 8.25 MN/sq m (1200 psig) steam line. The nozzle was an austenitic stainless steel casting in conformance to material. The nozzle had numerous cracks on the inside and outside surfaces, and the cracks had penetrated through the wall thickness in several areas. The fracture surfaces had distinct beach markings delineating the crack front, representative of crack propagation stages. The cracks were transgranular and, unlike classical corrosion-fatigue cracks, exhibited branching, characteristic of chloride-induced SCC in austenitic stainless steels. The failure resulted from chloride-induced...