| Attribute | ASTM G31 Testing Standards | ISO 12473 Testing Standards |
|---|---|---|
| Standard Scope | Provides guidelines for laboratory immersion corrosion testing of metals and alloys in various environments. | Provides guidelines for the design, application, and testing of cathodic protection systems for steel in seawater. |
| Primary Focus | Evaluation of the corrosion rate and behavior of metals in controlled laboratory settings. | Focuses on the performance and effectiveness of cathodic protection systems in marine environments. |
| Test Environment | Laboratory-based, with controlled chemical composition, temperature, and agitation of test solutions. | Field-based, simulating real-world marine conditions, including seawater composition, temperature, and biofouling. |
| Materials Covered | Primarily metals and alloys, including steel, aluminum, copper, and nickel. | Primarily steel structures exposed to seawater, including ships, offshore platforms, and pipelines. |
| Testing Procedure | Detailed procedures for sample preparation, immersion time, data collection, and analysis of corrosion products. | Includes guidelines for system design, anode selection, installation, and monitoring of cathodic protection systems. |
| Corrosion Rate Measurement | Corrosion rate is measured using weight loss, electrochemical methods, and surface analysis techniques. | Performance is evaluated based on the effectiveness of reducing or preventing corrosion, typically measured by potential. |
| Relevance to Industry | Widely used in research and development, material selection, and quality control across multiple industries. | Essential for marine engineering, ensuring the longevity and safety of steel structures in seawater. |
| Data Interpretation | Provides detailed guidance on interpreting corrosion data, including factors like pitting, uniform corrosion, and galvanic effects. | Emphasizes the long-term monitoring and adjustment of cathodic protection systems based on real-time data. |
| Application Limitations | Primarily applicable to laboratory settings; results may not directly translate to field conditions. | Specifically designed for marine environments; may not be applicable to other types of corrosion environments. |
| Complementary Standards | Often used in conjunction with other ASTM standards related to corrosion testing and material performance. | May be used alongside other ISO standards related to cathodic protection, such as ISO 15589. |
| Global Acceptance | Widely recognized and used in North America and internationally in various industries. | Recognized globally, particularly in industries related to marine and offshore engineering. |
| Documentation and Reporting | Provides detailed guidelines for reporting corrosion test results, including test conditions, data, and analysis. | Emphasizes the documentation of system design, installation, and performance monitoring over the lifecycle of the structure. |
ASTM G31 focuses on laboratory-based corrosion testing of metals, while ISO 12473 is tailored for assessing and maintaining cathodic protection systems in marine environments.