Alcoa has unveiled a new temper for marine sheet aluminium specifically designed to provide both commercial and naval shipbuilders with improved corrosion resistance.
An addition to the established Nautic-AL family of marine sheet products, the "H128" brand of fulfils the requirements of an accelerated corrosion test specified by the United States Navy to provide resistance to sensitisation, and to contribute to vessels meeting and exceeding their planned service life.
"Under certain conditions, such as exposure to high temperatures, marine alloys may become susceptible to inter-granular and exfoliation corrosion," commented Alcoa.
"Regular, prolonged, periods of high deck temperatures have been recorded on naval vessels and corrosion, in combination with the stress endured during the long service life of a vessel, can lead to cracks in both painted and unpainted ship hulls. This inevitably leads to higher maintenance costs or substantial repair costs to remedy water intrusion."
According to the company, Nautic-AL H128 provides significant thermal stability and higher corrosion resistance, reducing risk and lowering maintenance and repair costs.
Additionally, building with H128 offers the possibility of cost saving through less painting costs and simplified warranty plans.
Alcoa is the first manufacturer to register this new temper, developed through a two-year collaboration program between Alcoa's technical and manufacturing facilities in Fusina, Italy, and Davenport, USA. Both plants are capable of producing the new temper in a wide range of thicknesses and widths.
The temper has been registered at the US Aluminium Association, and successfully passed the ASTM B928/B928M ballots. It also received the marine certificate for civil shipbuilding from classification society Lloyd's Register.
