ELECTROCHEMICAL BEHAVIOUR OF AISI 304 STAINLESS STEEL IN SULFURIC SOLUTION: EFFECTS OF ACID CONCENTRATIO

The effects of h2so4 concentration on the electrochemical behaviour of passive films formed on aisi 304stainless steel were investigated using by potentiodynamic polarization, mott–schottky analysis and electrochemicalimpedance spectroscopy (eis). potentiodynamic polarization indicated that the corrosion potentials were found toshift towards negative direction with an increase in solution concentration. also, the corrosion current densitiesincrease with an increase in solution concentration. mott–schottky analysis revealed that the passive films behave asn-type and p-type semiconductors at potentials below and above the flat band potential, respectively. also, mott–schottky analysis indicated that the donor and acceptor densities are in the range 1021 cm-3 and increased withsolution concentration. eis data showed that the equivalent circuit rs(qdl[rct(rrqr)]) by two time constants isapplicable.