Common applications in ships and marine engineering:

- Seawater piping: 2205 or copper-nickel alloy; 316L only for low-flow, low-chloride environments. - Deck equipment and railings: 316L, with brushed or passivated surface for easy maintenance. - Chemical tanker cargo tanks: select 316L, 2205, 904L, or duplex steel according to cargo type.

Requirements: - Pickling and passivation are mandatory after welding; weld seams are corrosion initiation points. - Avoid direct contact with carbon steel (galvanic corrosion); use insulating pads. - Periodically inspect for pitting and crevice corrosion, especially in ballast tanks and seawater valves.

Standards reference: Classification society rules (CCS/DNV/ABS) set clear requirements for materials and welding.