The gaseous dissolution products of iron carbide in acid solutions were analyzed to supplement a study of dissolution of carbides.1,2 Results of the analyses were compared to those predicted from thermodynamic calculations after Pourbaix.3 Iron-carbide alloys were dissolved at constant potential to maintain constant oxidizing conditions throughout the test.
Previous results indicate that carbide dissolution products are a function of oxidizing tendency of the solution. Steel dissolved in acid yielded gaseous products comprised primarily of hydrogen with methane, carbon monoxide, and traces of other hydrocarbons and carbon dioxide.4 Uranium carbide dissolved in highly oxidizing environments of 2-16 M nitric acid yielded carbon dioxide and no hydrocarbons.5 The composition of gaseous products from thorium carbide shifted from hydrocarbons in dilute nitric acid to carbon oxides in concentrated nitric acid.6 Both reduction products (hydrocarbons) and oxidation products (carbon oxides) were reported at intermediate acid concentrations.
In this...
