Investigation on Effect of Aluminum on the Corrosion Resistance of Hadfield Austenitic Manganese Steel

In this study, the corrosion resistance of ASTM A-128 Hadfield manganese steel with and without aluminum addition was investigated. To produce Hadfield manganese steel according to ASTM A-128 standard, Initially two Y-shaped aluminum models prepared and then molding accompolished through Sodium Silicate/CO2 and silica sand procedure by closed feeding. Coreless induction furnace was used for melting samples. After casting, samples heat treated at 1100°C for 2 hours and then quenched in the pure water. Evaluation of the microstructures was conducted by optical metallography and corrosion morphology of samples were investigated by scanning electron microscopy. Also potentiodynamic polarization and electrochemical impedance spectroscopy methods were used to evaluate the corrosion behavior of samples. Optical microstructur observations showed that Al decreased the amount of carbides and increased grains size in the Hadfield steel. The results of corrosion tests indicated that Hadfield steel with aluminum addition had higher corrosion resistance than one without aluminum addition. By addition of aluminum, carbide particle volume was reduced and this has led to lesser micro-galvanic cells formation.