Shipbuilding & Offshore

Seawater is the harshest natural electrolyte: roughly 19,000 ppm chloride combined with wet-dry cycles and crevices. Here the first criterion is not strength — it is whether the material resists crevice corrosion.

Describe your application View products

Typical Components and Material Selection

Component	Steel Grade	Finish / Dimensions	Notes
Deck railings / fittings	316L	Tube / profiles, polished	Salt spray, post-weld passivation
Seawater piping	2205 / 6Mo	Seamless / welded pipe	Pitting, flow erosion
LNG tank inner shell	304L / 304	Plate 8–50 mm	Low-temperature toughness, class approval
Accommodation / galley equipment	304 / 316L	0.8–2 mm, 2B/HL	Cleanability, fingerprint resistance
Clamps / fasteners	316 / 2205	Bar / forgings	Stress corrosion cracking

These are common configurations.Actual selection depends on environment, temperature and welding method— The same component may move from 304 to 316L or 2205. Describing the service conditions is more useful than listing steel grades.

Three Practical Constraints in This Industry

Crevice corrosion is the primary failure mode

Under gaskets and at contact points between brackets and hull, 304 rusts within months. By design, eliminate crevices (continuous welds, drain holes) and upgrade to 316L or 2205.

Confirm class approval as early as possible

DNV / ABS / LR / CCS each maintain their own approved material lists. A better grade that is not approved still fails inspection — please check at the quotation stage.

Welding distortion accumulates through to assembly

Thin-wall outfitting components distort and accumulate tolerance errors during final assembly. Pre-fabricate by sub-block with anti-distortion jigs, and leave machining allowance.