Sour Service Corrosion Testing for NACE MR0175/ISO 15156 Compliance

Element delivers comprehensive sour service testing solutions that address all aspects of material performance in H2S environments. Our testing capabilities include advanced methodologies and specialized procedures:

• SSC testing at ambient temperature
• Full ring testing
• SOHIC testing
• Stress Corrosion Cracking (SCC), Pitting and Crevice tests in High Pressure High Temperature (HPHT) environments up to 250 °C and 300 bar
• Slow Strain Rate (SSRT) and Rippled Slow Strain Rate (RSSR) testing
• Customer-specific services; advice and guidance, consultancy and bespoke testing programs

Testing to NACE MR0175 / ISO 15156 Requirements

Testing and qualification under ISO 15156/NACE MR0175 are divided into two categories:

1. Carbon and Low Alloy Steel Testing

Part 2 of the standard outlines testing and qualification for:

• Sulfide Stress Cracking (SSC)
• Hydrogen-Induced Cracking (HIC Testing)
• Stress-Oriented Hydrogen-Induced Cracking (SOHIC)

For these cracking modes, susceptibility is highest at ambient temperature. Key environmental factors to consider include solution pH and the partial pressure of H₂S.

2. Corrosion-Resistant Alloy Testing

Part 3 of the standard covers testing and qualification for:

• Sulfide Stress Cracking (SSC)
• Stress Corrosion Cracking (SCC)
• Galvanically-Induced Hydrogen Stress Cracking (GHSC)

For stress corrosion cracking, the most significant susceptibility occurs at ambient or low temperatures. For other types, susceptibility is usually highest at maximum operating temperatures. In duplex stainless steels specifically, the highest risk occurs at intermediate temperatures (80–100°C).

Critical environmental factors for corrosion-resistant alloys include solution pH, chloride concentration, and partial pressure of H₂S, with temperature playing a significant role in susceptibility.

Our testing capabilities cover the complete range of materials and components used in sour service environments. We evaluate everything from carbon and low alloy steels to advanced corrosion-resistant alloys, including:

• Complete pipeline systems and components
• Storage vessels and containment systems
• Welded structures and assemblies
• Specialty alloys and custom materials
• Full-scale component testing under simulated conditions

Our approach combines traditional and advanced testing methods to provide comprehensive material qualification. We offer customized solutions that address your specific operational conditions:

Our testing capabilities include advanced methodologies conducted in accordance with NACE TM0177 (SSC/SCC/GHSC), NACE TM0316 (SSC/SCC), NACE TM0284 (HIC), NACE TM0198 (SSRT) and BS8701 (Full Ring):

• Environmental simulation at ambient temperatures (critical for carbon/low alloy steels)

• Elevated temperature testing (80-100°C focus for duplex stainless steels)

• pH and H2S partial pressure variation testing

• Chloride concentration impact assessment

• Galvanically-induced hydrogen stress cracking evaluation

• Corrosion inhibitor selection and testing

• Custom test program development

• Detailed performance analysis and recommendations

Research and development capabilities
Our industry-leading R&D programs advance testing methodologies and solutions:

• Development of new SOHIC testing protocols
• Innovation in SSC testing using axial loading full ring tests
• Custom testing program development
• Material performance optimization studies
• Advanced analytical techniques for real-world conditions
• Correlation studies between different test methods
• Specialized corrosion inhibitor evaluation

Our state-of-the-art facilities feature specialized equipment and environmental controls designed specifically for sour service testing:

• Advanced HPHT testing chambers with environmental monitoring
• Environmental control systems for precise H2S levels
• Full ring testing apparatus
• Specialized corrosion monitoring equipment
• Custom test fixtures for unique geometries
• Real-time data acquisition systems

Element has an integrated global network of laboratories that offer the complete range of sour-service tests for the qualification of your materials to the requirements of MR0175 / ISO 15156. Find your nearest Materials Testing Services hub on our Locations Page.