On the pitting corrosion of tin in aqueous solutions

摘要: Abstract Four independent techniques were employed to prove that Sn undergoes pitting corrosion. The first was based on the measurement of variation open circuit potential electrode in aerated Cl− solutions various concentrations. Steady-state potentials attained slowly and erratically from negative values, more positive higher dilution. electrodes prepassivated CrO42− responded readily additions ion. developed noble than those measured presence passivator alone, changed values with increase concentration corrosion agent. Attack under cathodic control. Galvanostatic polarization Sri carried out 0.005 0.1M NaOH, Cl−. Above a certain content, contingent upon alkali concentration, aggressive anion prevented evolution Oa electrode, oscillations E−t curves recorded. Competitive adsorption OH− is assumed occur, which affected both quantity electricity, Qp, consumed along oxide formation steps, rate increase, dE/dt, following oxidation. Plots two variables as function ion exhibited definite break at value characteristic for initiation attack. Potentiodynamic showed progressively shifts towards agent solution increased. currents resulting addition measured. dependence maximum composition explained basis competitive adsorption.