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.

Abstract: Although high-manganese steels may have desirable mechanical strength and corrosion resistance, machining and casting can be difficult. Alternatively, high-manganese steel parts may be fabricated to near-net shape parts using powder metallurgical processing, such as hot pressing and powder injection molding, thereby significantly minimizing or eliminating the need for further machining of fabricated parts.

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.

Abstract: Conduit system for conveying fluids is described. The conduit system comprises a conduit, a tubular, and a sealing component. The tubular is positioned radially interior of an inner surface of the conduit along a length. The tubular comprises a polymeric material. The sealing component is positioned proximate the distal end of the tubular in an annulus formed between an outer surface of the tubular and the inner surface of the conduit, the sealing component constructed and arranged to seal the annulus. Methods for reducing corrosion of or providing pressure integrity to a conduit are also described.

Abstract: Conduit system for conveying fluids is described. The conduit system comprises a conduit, a tubular, and a sealing component. The tubular is positioned radially interior of an inner surface of the conduit along a length. The tubular comprises a polymeric material. The sealing component is positioned proximate the distal end of the tubular in an annulus formed between an outer surface of the tubular and the inner surface of the conduit, the sealing component constructed and arranged to seal the annulus. Methods for reducing corrosion of or providing pressure integrity to a conduit are also described.