Specific Effect of Metal Cations on Stress Corrosion Cracking

The specific effect of certain cations on stress corrosion cracking (SCC) has been observed in many systems.  In particular Ag-Cd alloys are known to be susceptible to SCC in silver nitrate aqueous solutions, at the equilibrium potential of Ag.  The aim of the present work was to find out if this is a more general phenomenon; and to this purpose, Ag-20Zn (at/o) samples were tested in solutions containing Ag+ ions at the equilibrium potential of Ag. SCC was found, and the crack propagation rate was a function of the Ag+ ion concentration.Fil: Farina, Silvia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Duffó, Gustavo Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Galvele, Jose Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto Sabato; Argentin

Stress Corrosion Cracking of Zircaloy-4 in Halide Solutions: Effect of Temperature

Zircaloy-4 was found to be susceptible to stress corrosion cracking in 1 M NaCl, 1 M KBr and 1 M KI aqueous solutions at potentials above the pitting potential. In all the solutions tested crack propagation was initially intergranular and then changed to transgranular. The effect of strain rate and temperature on the SCC propagation was investigated. An increase in the strain rate was found to lead to an increase in the crack propagation rate. The crack propagation rate increases in the three solutions tested as the temperatures increases between 20 and 90 °C. The Surface-Mobility SCC mechanism accounts for the observation made in the present work, and the activation energy predicted in iodide solutions is similar to that found in the literature