Overview
ISO 21207:2015 specifies two accelerated corrosion test methods for evaluating the corrosion resistance of products containing metals when exposed to chloride contamination (sodium chloride from marine or de‑icing sources) in combination with corrosion‑promoting gases typical of industrial and traffic atmospheres. The standard defines the required test apparatus, test cycles (alternate exposure to neutral salt‑spray, corrosive gas atmospheres and drying), and evaluation procedures. Methods are optimized for sensitive metallic products such as electronic components used in traffic, industrial and marine‑influenced environments.
Key topics and technical requirements
- Test methods A and B:
- Method A: simulates a moderately aggressive traffic environment - includes a short neutral salt‑spray step followed by an extended exposure to a wet gas atmosphere and drying.
- Method B: simulates a more severe industrial/traffic environment - involves repeated cycles of salt spray and corrosive gas exposure.
- Salt spray step: neutral salt spray (ISO 9227) using a 5 % NaCl solution at 35 °C, typically 2 h per salt‑spray cycle followed by controlled drying periods.
- Gas exposure step: test atmosphere containing low concentrations of nitrogen dioxide (NO2) and sulfur dioxide (SO2) at high relative humidity (≈95 %) and 25 °C; gas exposure durations differ between methods (method A uses a single long exposure; method B uses two shorter exposures).
- Apparatus and control:
- Climatic cabinet and gas flow system compliant with ISO 10062.
- Uniform temperature (±1 °C), relative humidity (±3 %) and airflow; monitored NO2/SO2 concentrations at the chamber outlet.
- Salt spray equipment per ISO 9227.
- Drying in standard laboratory climate (23 °C ±2 °C, RH 50 % ±5 %).
- Reference and evaluation:
- Use of copper reference panels and mass‑loss evaluation following ISO 8407; specimen handling and positioning rules ensure reproducible corrosivity assessment.
Applications and users
- Typical users: corrosion test laboratories, electronic and electrical component manufacturers, automotive and transport OEMs, marine equipment producers, and materials/corrosion engineers.
- Practical uses:
- Pre‑qualification of products for service in road‑salt, coastal or polluted urban environments.
- Comparative screening of coatings, finishes and metal alloys for resistance to combined salt and gaseous corrosive attack.
- Supporting design decisions and quality control for assemblies with sensitive metallic parts.
Related standards
- ISO 9227 - Salt spray tests
- ISO 10062 - Corrosion tests in atmospheres with low pollutant concentrations (climatic cabinet requirements)
- ISO 8407 - Removal of corrosion products (cleaning and mass‑loss measurement)
- ISO 10289 - Rating of specimens after corrosion tests
Keywords: ISO 21207:2015, accelerated corrosion tests, neutral salt‑spray, corrosion‑promoting gases, NO2, SO2, salt spray testing, corrosion resistance testing, climatic cabinet, electronic components.