Potential-pH Diagram and SCC

Critical potentials for SCC of a metal/solution system can be related to its -pH diagram as these diagrams describe the conditions at which film formation and metal oxidation occur. The potential-pH (fi-pH) diagram of carbon steel shows that SCC is associated with potentials and pH values at which phosphate, carbonate, or magnetite films are stable, while Fe + and HFeOJ are metastable. A comparable diagram exists for a 70 Cu-30 Zn brass in a variety of solutions (96). 

The E-pH diagram of the cracking metal/solution interface is a useful tool in the evaluation and understanding of the mechanism of SCC although it is difficult to evaluate in a precise manner. The -pH behavior of the crack tip solution interface is substantially different from that in bulk solution (97-99). 

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Potential-pH diagram and SCC. Critical potentials for SCC of a system metaFsolution can be related to its -pH diagram, because these diagrams describe the conditions at... 

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