Overview
ISO 7384:1986 - "Corrosion tests in artificial atmosphere - General requirements" specifies general requirements for laboratory corrosion tests carried out in controlled/accelerated artificial atmospheres. The standard covers specimen types, apparatus and procedural controls for testing metals and alloys with or without permanent or temporary corrosion protection. ISO 7384 is intended as a baseline for other international test methods, accelerated testing procedures and for the design/construction of corrosion chambers.
Key topics and technical requirements
- Scope and classification: Defines three test types - optimized (simulate service mechanism accelerated), short‑term (comparative accelerated), and rapid quality‑control tests.
- Specimens: Consistent shape, dimensions and surface condition; preferred thickness 0.5–3 mm; minimum total specimen area normally ≥ 25 cm²; cut edges to be deburred and usually protected unless edge effects are under study.
- Chamber and apparatus:
- Chambers must ensure homogeneous, uniform exposure; upper chamber profile prevents condensate dripping onto specimens.
- Humidification using distilled or de‑ionized water only; humidity ramp to target ≤ 1 hour.
- Temperature/humidity control accuracy: ±2 °C and ±5 % RH.
- Air circulation to equalize conditions; materials in contact with corrosive agents must be resistant.
- Avoid cross‑contamination (e.g., volatile corrosion inhibitors require dedicated chambers).
- Maximum specimen surface area guideline: 0.75 m² per m³ of chamber volume.
- Exposure and monitoring:
- Recommended exposure durations include 24, 48, 96, 240, 480, 720, 2016 hours depending on objective.
- Records of temperature, relative humidity and active corrosive agent concentrations should be automatic or periodic.
- Measurements and evaluation:
- Evaluation criteria include visual appearance, time to first corrosion, number/distribution of defects, mass change (ISO 8407 referenced), dimensional and property changes.
- Weighing precision: ±0.001 g for specimens ≤ 200 g; ±0.01 g for heavier specimens.
- Test report: Must include test purpose, method, specimen description, exposure conditions, measurements and evaluation criteria.
Applications and users
ISO 7384 is used by:
- Corrosion testing laboratories and R&D teams conducting accelerated corrosion assessments
- Manufacturers of metals, alloys and protective coatings for qualification and comparative testing
- Quality‑control and failure‑analysis engineers
- Designers and builders of corrosion chambers seeking baseline design and control requirements
- Standards committees referencing general requirements in specific corrosion test methods
Related standards
Standards referenced in ISO 7384 include (examples):
Keywords: ISO 7384:1986, corrosion tests, artificial atmosphere, corrosion chambers, accelerated corrosion testing, metals and alloys, specimen preparation, evaluation criteria.
