Overview
ISO 17804:2020 - "Founding - Ausferritic spheroidal graphite cast irons - Classification" defines the classification, grades and requirements for ausferritic spheroidal graphite cast iron (austempered ductile iron, ADI). The standard specifies five grades based on mechanical properties and two additional grades defined by hardness. It covers sampling, manufacture, testing methods and designation rules for test pieces obtained from separately cast samples, side-by-side/cast‑on samples, or samples cut from a casting.
Key topics and requirements
- Grade classifications: Five grades by mechanical properties (tensile, elongation, impact) and two grades by hardness (abrasion‑resistant grades).
- Sampling methods: Requirements for separately cast samples, side‑by‑side cast samples, cast‑on samples and samples cut from castings, including sample size, frequency and test-unit formation.
- Manufacture and heat treatment: Guidance on production and austempering to develop the required ausferritic matrix and graphite morphology.
- Mechanical testing: Prescribed methods for tensile testing, Charpy impact testing, and Brinell hardness testing (references to ISO 6892‑1, ISO 148‑1, ISO 6506‑1).
- Microstructure requirements: Graphite classification and matrix structure checks (graphite form, nodularity) per ISO 945‑1 and annex guidance.
- Test-piece preparation: Machining and conditioning of test pieces from different sample types, plus rules for retests and test validity.
- Ancillary provisions: Annexes provide abrasion‑resistant grades (Annex A), hardness range procedures (Annex D), guidance tables (Annex C, E), nodularity criteria (Annex H/I) and additional mechanical/physical information.
Applications and users
ISO 17804:2020 is intended for:
- Foundries producing ADI alloys requiring standardized grade declaration.
- Materials and metallurgical engineers specifying mechanical and microstructural requirements.
- Quality control and testing laboratories performing tensile, impact and hardness tests and microstructure examinations.
- Designers and OEMs in industries that use high‑strength, tough or wear‑resistant castings (mining, earth‑moving equipment, manufacturing, pressure equipment where applicable).
- Procurement and conformity assessors requiring unambiguous order information and acceptance criteria.
Practical benefits include consistent material selection, traceable test procedures, and clear acceptance criteria for wear‑resistant or high‑strength ADI components.
Related standards
Keywords: ISO 17804:2020, ausferritic spheroidal graphite cast iron, ADI, classification, grades, hardness, tensile test, Brinell, impact test, foundry standards.
