5083-H116 aluminum
Product-specific reference for marine 5083-H116, corrosion-test acceptance, property scope and fabrication limits.
Tags: materials, aluminum, marine, corrosion
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Specify alloy, temper and product requirements
Hydro's Njørdal H116 (May 2020), a 3–8 mm 5083 product, lists 220 MPa minimum versus 250 MPa typical proof stress, and 305 MPa minimum versus 340 MPa typical tensile strength as delivered. Minimum elongation is 10% on its proportional gauge-length basis. Hydro gives a separate H111 strength basis after welding and makes binding properties subject to the delivery specification. Hydro Njørdal H116 data
5083-H116 combines a wrought aluminium-magnesium alloy designation with a controlled delivery condition used for marine applications. Hydro describes 5083 as non-heat-treatable: strength comes from alloying and strain hardening rather than precipitation ageing. The alloy appears principally as sheet/plate, with some extrusion applications; properties from one product form should not be transferred to another. Hydro 5083 alloy
The Australian Aluminium Council's Rolled Products Manual, January 2024, describes special corrosion-resistant H321 processing and identifies H116 as another temper used for that application. H116 and H321 remain distinct designations: do not treat similar strength figures or the same intended application as approval to substitute one for the other. AAC temper definitions, p. 10
Product specification versus test method
ASTM B928/B928M-15(2023)e1 covers specified high-magnesium alloy-temper products intended for marine hulls and other frequent or continuous seawater contact. Its public scope includes flat/coiled sheet, plate and listed extruded products. It distinguishes these from other potentially suitable marine products that may not require its corrosion testing. Therefore, a generic 5083 certificate or a different product standard is not evidence of B928 compliance. ASTM B928/B928M scope
The B928 abstract describes inspection lots, identification and corrosion acceptance. Obtain the full ordered specification and relevant test documentation; its public abstract is not a substitute for sampling rules, acceptance limits or the contract requirements. A mill's capability to supply marine material and certification of a particular delivered lot are different claims. ASTM B928/B928M inspection context
The two commonly discussed corrosion methods assess different phenomena:
| Method | What it assesses | What a result does not establish |
|---|---|---|
| ASTM G66-23, ASSET | Visual exfoliation-corrosion susceptibility of wrought 5xxx Al-Mg products containing at least 2% Mg | All corrosion modes or a universal service life |
| ASTM G67-24a, NAMLT | Intergranular-corrosion susceptibility by mass loss after nitric-acid exposure | A seawater corrosion rate or a complete assembly qualification |
ASTM describes G66 as useful for alloy development and mill-product quality control, and G67 as a quantitative susceptibility measure. Record method edition, specimen preparation/location, conditioning, units, result and the acceptance specification. A method designation by itself contains no evidence that the delivered lot passed. ASTM G66, ASTM G67
G67 explains the importance of an aluminium-magnesium second phase and its continuity at grain boundaries. This is a metallurgical susceptibility test, not a statement that every surface pit has the same cause. Assessment of an exposed or heat-affected component needs its processing and service history as well as appropriate examination. ASTM G67 significance and use
A bounded supplier example
Hydro’s Njørdal sheet gives typical density 2.66 g/cm³. As an original estimate, an uncoated 1,000 × 500 × 6 mm blank has volume 0.003 m³ and mass 0.003 × 2,660 = 7.98 kg. Tolerances, cutouts and coatings change the actual value. Hydro physical-property data
Fabrication changes the assessment
Do not assume delivery-temper strength survives welding unchanged. Hydro's example explicitly supplies separate after-welding properties, describing strength as that of H111. A welding route needs an appropriate procedure, filler selection, joint design and inspection; the unwelded certificate alone cannot qualify it. Hydro after-welding data
Likewise, qualify bending with actual gauge, direction, tooling and surface condition. The named Hydro product recommends larger bend radii; that is not a universal radius table for other thicknesses or products. Do not replace a specified H116 condition with a softer temper solely to simplify forming without approval of the resulting part.
Machining, welding, local heating and thermal service should remain visible in the material record. Assess whether the final condition still meets the required strength and corrosion performance. This page supplies no universal safe heat-exposure duration or temperature, heat-treatment recipe, welding parameter or machining feed.
Release for the intended service
Evaluate the complete assembly: environment, temperature history, sustained loads, welds, dissimilar-metal contacts, crevices, drainage and any coating or cathodic-protection arrangement. Corrosion-qualified incoming stock does not eliminate these design and fabrication concerns.
Retain heat/lot traceability, certificates, corrosion acceptance records, weld and forming procedures, and final inspection results. Confirm the scope and validity of any classification approval independently of a general marine-product description. A corrosion-test pass, an application listing and an approved vessel/component are separate facts.
Sources were reviewed November 1, 2026. The Hydro sheet's printed May 2020 version is retained; web upload or search dates are not treated as a new product qualification.