Comments on the 'Stress corrosion cracking of zirconium and zircaloy-4 in halide aqueous solutions' by S.B. Farina, G.S. Duffo, J.R. Galvele

The above paper [Corros. Sci. 45 (2003) 2497] declares a general approach to describing stress corrosion cracking (SCC) mechanism and despite of the criticism of the so-called “surface mobility mechanism” (SMM) e.g., [Corros. Sci. 36 (1994) 669, Corros. Sci. 45 (2003) 2105]. The paper [Corros. Sci. 45 (2003) 2497] demonstrates inner contradictions and mutually excluding statements of SMM when fitted calculated and measured values of crack propagation rate. As shown in these Comments, the crack propagation rate calculated using SMM is only the Nabarro–Herring creep deformation rate, which can never be numerically equal to the crack propagation rate. Thus, tests undertaken by the author of SMM cannot be accepted as experimental evidence of the SMM.