Abstract
A study has been made of film formation and stress-corrosion cracking in alpha-brasses containing 20 and 30 wt pct Zn in certain aqueous citrate and tartrate solutions. The results indicate that exposure to both environments leads to the formation of a tarnish film of cuprous oxide, similar to that formed in ammoniacal solutions. Ellipsometric studies indicated that the rate of tarnish growth is greater for the tartrate solution than the citrate, and that both rates are small compared to that for ammonical environments; the rates of tarnish growth in both solutions were greater for Cu-30 than for Cu-20 Zn. Stress-corrosion tests confirmed the earlier report of Johnson and leja that Cu-30 undergoes intergranular cracking in both solutions, failure being more rapid in the citrate case, but indicated that no failures occurred in Cu-20 Zn in times up to 1000 hr. These results are discussed in terms of the tarnish-rupture mechanism for stress-corrosion cracking.
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E. N. PUGH, formerly with RIAS
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Green, J.A.S., Pugh, E.N. The role of tarnishing in the stress-corrosion cracking of alpha-brass in aqueous citrate and tartrate solutions. Metall Trans 2, 1379–1383 (1971). https://doi.org/10.1007/BF02913363
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DOI: https://doi.org/10.1007/BF02913363