| Abstract: | Influence of the composition of brass on dezincification and intercrystalline corrosion in ammonium chloride solutions The intercrystalline corrosion of As-containing α-brass is not restricted to a defined brass composition but is found also with brass types containing, in addition, AL and Sn. In the case of two-phase alloys of this type the β-phase is preferentially corroded, in Particular when the brass contains As and the β-phase forms a coherent network. On the basis of the results obtained a hypothesis has been derived as to mechanism the partial processes; this hypothesis is confirmed by result obtained with macroelements of As-containing and As-free brass. According to this hypothesis the intercrystalline corrosion of α- brass can be ascribed to the inhibition by As of the dezincification, so that no regions more anodic than grain boundaries are formed. This is why the boundaries are attacked preferentially. |
