Overview
ISO 11997-2:2013 - Paints and varnishes - Determination of resistance to cyclic corrosion conditions - Part 2: Wet (salt fog)/dry/humidity/UV light - defines a laboratory test method to assess how coatings resist a defined cycle of salt fog, drying, humidity and UV light exposures. The procedure uses a specified spray solution and alternating exposure in an artificial weathering (UV/condensation) cabinet and a cyclic corrosion (salt fog/dry) cabinet to provide reproducible accelerated corrosion/UV stress results. This part is equivalent to ASTM D5894.
Key topics and technical requirements
- Test cycle: Alternating exposure in an artificial weathering cabinet (UV/condensation) and a cyclic corrosion cabinet (salt fog/dry). The artificial weathering cycle is 4 h light (UV) / 4 h condensation at a black panel temperature of 60 °C and condensation at 50 °C (UVA 340 lamps by ISO 16474-3).
- Corrosion cabinet cycle: Typical cycle is 60 min salt fog at ambient temperature followed by 60 min dry at 35 ± 2 °C; salt fog deposition rate 1–2 ml/h (collected over 24 h) per ISO 11997-1.
- Total test time: Default example is 1 008 h (6 weeks) achieved by repeating UV and corrosion exposures (168 h in each cabinet per cycle) unless otherwise specified.
- Spray solution: Prepare with c(NaCl) = 0.50 ± 0.01 g/L and c[(NH4)2SO4] = 3.50 ± 0.01 g/L using ISO 3696-grade water; salts must meet specified purity limits (total impurities ≤ 0.5 %, iodine ≤ 0.1 %, Cu/Ni ≤ 0.001 %). Filter before use.
- Specimens and preparation: Burnished steel panels (minimum 150 × 70 × 0.3 mm), coated per ISO 1514; drying/conditioning per ISO 3270; film thickness measured per ISO 2808; scribing per ISO 17872 if required.
- Replication and controls: Tests in triplicate; include at least one control specimen (recommended two controls of differing durability).
- Evaluation: Examine per the ISO 4628 series (blistering, rusting, cracking, flaking, delamination, filiform corrosion). Test report must document cycles, solution, panel prep, application, and results.
Applications and users
- Practical for quality control, comparative performance testing, product development and R&D of industrial, maintenance, marine and automotive coatings.
- Common users: coating manufacturers, independent test laboratories, specification writers, R&D teams and certification bodies seeking reproducible accelerated data on combined UV and cyclic corrosion resistance.
Related standards
Keywords: ISO 11997-2:2013, cyclic corrosion testing, salt fog, UV exposure, paints and varnishes, accelerated corrosion testing, coating resistance, artificial weathering.