Overview
ISO 115:2024 - Unalloyed aluminium ingots for remelting - Classification and composition - sets international requirements for grades of unalloyed (refined) aluminium ingots intended for remelting. The standard specifies grade designations and chemical composition limits, production and quality-control responsibilities, inspection and sampling procedures, marking, packaging and delivery documentation. It replaces ISO 115:2003 and expands grade coverage.
Key topics and technical requirements
- Classification and composition: Defines grades of unalloyed aluminium (e.g., high-purity Al 99.995 down to Al 99.70 and P‑series designations) with maximum mass fractions for main impurities. Writing rules for designations are given in Annex A.
- Quality control: The supplier is responsible for inspection and tests before shipment; purchaser inspection must be agreed at ordering.
- Sampling and analysis:
- Samples should be representative of the melt; at least two analytical samples (beginning and end of each melt) are required.
- Samples must be machined and, for emission spectrometry, sparked multiple times with the arithmetic mean reported.
- Results must be traceable to reference materials and retained for a minimum period (test reports retrievable for at least three years).
- Trace impurities: Limits and monitoring for hazardous trace elements (e.g., Cd, Hg, Pb, As) are specified by footnotes; producers should monitor Na and Li (reported to four decimal places where relevant) due to casting/rolling sensitivity.
- Freedom from contamination: Ingots must be free from hazardous foreign materials, asbestos and increased radioactivity; acceptable surface conditions and inclusion tolerances must be agreed between parties.
- Form, marking and safety:
- Ingot shapes (trapezoidal, T‑bars, sows) and dimensions are defined by agreement.
- Each ingot and/or bundle must carry manufacturer identity and grade designation; marking must be indelible and non‑contaminating.
- Bundles must include warnings to dry and preheat ingots before melting to avoid explosive water entrapment.
Practical applications and users
- Primary users: aluminium producers, remelters, foundries, metal traders, material specifiers and quality managers.
- Use cases:
- Specifying incoming feedstock for remelting and alloy production.
- Establishing supplier contracts and order details (designation, unit mass, melt number).
- Laboratory sampling, chemical analysis protocols and certificate preparation.
- Ensuring safety and regulatory compliance in secondary aluminium operations.
Related standards
- ISO Guide 30 (reference material/certified reference materials) is relevant for traceability of analytical results. Purchasers and suppliers commonly reference national analytical standards for sampling/analysis methods as noted in ISO 115:2024.
Keywords: ISO 115:2024, unalloyed aluminium ingots, remelting, classification, chemical composition, sampling, quality control, trace impurities, ingot marking, inspection certificate.