The Effect of Cu and Mo on Mechanical Properties and Corrosion Resistance of Austempered Ductile Iron

Abstract

The metal casting is the most economical manufacturing process. It can make products with complex geometries in one process. Austempered Ductile Iron (ADI) is a cast iron product that has high prospects for application, because ADI has a high strength closed to forged iron. The purpose of this study is to investigate the effect of addition of Cu and Mo on mechanical properties and corrosion resistance of ADI. Cu is added with percentages of 0.5 and 1% by weight, while Mo is added by percentages of 0.3 and 0.6% by weight. The austempering process is conducted on salt bath temperture 350 <sup>o</sup>C for 4 hours. The results of the process were characterized by hardness test, tensile test and corrosion resistance. Hardness and tensile strength of ADI were tested by Brinell hardness test based on ASTM E10 and ASTM E8 repectively. Corrosion resistance of ADI was tested by immersion corrosion testing based on ASTM G31 standard. The results of this study indicate that the addition of Cu element significantly increases the strength of ADI. The addition of Mo element inhibits graphite nodularity and not significantly increases the mechanical properties. Addition of Mo increases corrosion resistance due the amount of retained austenite.