Studies on corrosion behaviour of Cu-Si alloys in Sulphide and Chloride media

Introduction It is well established that Si in silicon bronzes imparts high strength and corrosion resistance which are essential requirements for applications in hydraulic pressure lines, heat exchangers, propeller shafts, storage tanks and other equipments for chemical industries. They have high corrosion resistance towards marine environments, but possess inferior corrosion resistance in sulphide bearing atmosphere although more resistant to stress corrosion cracking and season cracking than brass on exposure to polluted atmospheres. In general, corrosion resistance of alloys depends on alloy chemistry, heat treatment schedule, presence of second phase, precipitation morphology and specific environment. However, studies on influence of heat treatment and variation of silicon content in (Binary) Cu-Si alloys with particular reference to their corrosion resistance in chloride and sulphide bearing environments are scanty in literature. The present work has been designed to study the corrosion behaviour and to generate data on three types of commercially important Cu-Si alloys in 3.5 per cent sodium chloride and 1 per cent sodium sulphide solutions.