Patent ID: 10947610

Abstract:
Mooring chains used in offshore environments are typically formed from carbon steels due to their wear and fatigue resistance properties. Although carbon steels may exhibit robust mechanical properties, they are susceptible to corrosion, which can shorten the usable working lifetime of mooring chains, particularly in a seawater environment. Austenitic steels comprising high percentages of manganese may have comparable mechanical properties to the carbon steels commonly used in mooring chains, yet exhibit less susceptibility to corrosion. Austenitic steels suitable for use in mooring chains and other structures in contact with or exposed to a seawater environment may comprise: 0.4-0.8 wt. % C, 12-25 wt. % Mn, 4-15 wt. % Cr, a non-zero amount of Si<3 wt. %, a non-zero amount of Al<0.5 wt. %, a non-zero amount of N<0.1 wt. %, <5 wt. % Mo, and balance Fe and inevitable impurities.