Three different grain sizes were used to deposit NiAl and Ni3Al intermetallic coatings on 304 type SS by thermal spraying powder and HVOF (High Velocity Oxygen Fuel) processes. Coatings were characterized by scanning electron microscopy and their characteristics are described as a function of particle size and coating process applied. The corrosion resistance of coatings was evaluated through open circuit potential, potentiodynamic polarization and linear polarization resistance tests in a 1.0 M NaOH solution at room temperature (25 °C). It was observed that the spray process and the particle size have an effect on the electrochemical behavior of coatings tested. Different coatings showed no significant variations in current densities, but were one order of magnitude greater than those of the base alloy; corrosion potentials of coatings were more negative than those of its base alloy regardless of particle size and have similar values.