Marine engineering is one of the more complicated technical sciences around – and part of the education for it is learning which materials are used in nautical vessels. Naval brass is one of them.
In the naval industry, brass is valued for its unmatched resistance to seawater corrosion. To suit marine environments, small amounts of other elements are added to brass to boost its performance, mostly for better corrosion resistance and durability. Higher zinc content, for instance, increases the alloy’s strength, while tin and arsenic improve its resistance against dezincification, a normal corrosive reaction in seawater.
Naval brass can generally be classified into two groups: alpha brass and alpha-beta brass. The former only has a single alpha phase structure with around 37% zinc, while the latter has both alpha and beta forms, with the beta part consisting of about 37.5% zinc.
Alpha brass is mostly used for wrought metalwork, which includes instrumentation lines and the hydraulic controls of marine systems. This type of brass easily cracks under extreme heat but performs well during marine exploration activities.
Naval brass is an example of a hot worked duplex alloy reinforced with tin and zinc to enhance its anti-corrosive properties, particularly for tube sheets in heat exchangers. Other ship parts that undergo hot working include marine hardware and propellers.