Mechanism of scc of α-brass in Mattsson's solution under potentiostatic conditions

Critical Potentials for Stress Corrosion Cracking of 63‐37 Brass in Ammoniacal and Tartrate Solutions

“…This conclusion is supported by the small amount of dissolved Cu + + (0.003M, Fig. Necessity for the presence of NH4 + has been demonstrated by early investigators and most recently by Lynes (2) and by Sircar et aL (15). It is also supported by differing critical potentials for failure depending on whether the available ammonium complex contains Cu ++, Cd ++, Zn + +, Ni + +, or Co + +.…”

“…); (it) progressive fracture of an oxide or other type reaction product film covering the alloy surface (9-13); or (iii) reduction of metal bond strength by an adsorbate (14,15), called by one of us "stress-sorption cracking" (16). ); (it) progressive fracture of an oxide or other type reaction product film covering the alloy surface (9-13); or (iii) reduction of metal bond strength by an adsorbate (14,15), called by one of us "stress-sorption cracking" (16).…”

Effect of Annealing on the Stress Corrosion Cracking of α-Brass in Aqueous Electrolytes Containing Aggressive Ions

“…The results also show that the alloy is strongly susceptible to SCC in NaNO 2 solutions, whether it was in the annealed or the as-received conditions, and the severity of cracking increases as the solution concentration increases and with anodic polarization (see Figure ). Anodic polarization can be expected to shorten the initiation time to fracture and is often found to increase the crack propagation rate. ,, Fractographic inspection shows that the mode of failure changes from intergranular at OCP to transgranular by anodic polarization. Relating the transformation of the mode of failure to the boundaries of the Pourbaix diagram for the Cu−H 2 O system , indicates the association of intergranular cracking with the Cu 2 O domain with transgranular cracking at potentials in the stability domain of CuO, with a mixed mode of cracking being observed in tests conducted near the boundaries of these two oxides (∼200 mV H ).…”

“…Relating the transformation of the mode of failure to the boundaries of the Pourbaix diagram for the Cu−H 2 O system , indicates the association of intergranular cracking with the Cu 2 O domain with transgranular cracking at potentials in the stability domain of CuO, with a mixed mode of cracking being observed in tests conducted near the boundaries of these two oxides (∼200 mV H ). Sircar et al reported that anodic polarization caused a minimum in cracking for annealed specimens, which was accompanied by a transition of the mode of cracking from intergranular to transgranular. Also, Alvarez et al suggested that anodic dissolution processes are controlling the SCC of brass in nitrite solutions.…”

Electrochemistry of stress corrosion cracking of brass

“…Failure can be attributed to the adsorption model, where specific species adsorb on and interact with strained bonds at the crack tip » causing a reduction in bond strength and permitting brittle fracture [45]. The adsorption model was adopted strongly by Sircar et al [129], who suggested that cracking pattern is dependent mainly on the situation existing at the surface or the interfaces of a corroding material and the environment, and that the conventional reactions of dissolution are of secondary importance in the cracking process, while adsorption plays a major role. Moreover, the production of NH^ ions, by cathodic reduc tion of nitrite and nitrate anions, was reported before [69,130].…”