Influence of Chromium and Nickel Variation on the Microstructure, Carbide Morphology and Corrosion Behaviour in Fe-Mn-Cr-Cu based Austenitic White Irons

摘要

The aim of the work is to develop a low-cost cast iron having comparable corrosion resistance with that of Ni-Resist cast iron but free from graphitic corrosion. In experimental alloys, austenitic matrix was found in both as-cast and heat treated conditions. The volume fraction of austenite also increased with increase of heat treatment temperature and time at temperature. X-ray diffractometry, energy dispersive analysis and optical microscopy were employed to investigate the microstructural features. Hardness testing and corrosion study were carried out. The corrosion rates were in the proximity of those of Ni-Resist irons especially on heat treatment at higher temperatures.