Materials & Components CompatibilityTara Camacho-Lopez
The materials and components compatibility program element applies Sandia’s core capability in hydrogen embrittlement to address fundamental questions about the mechanical behavior of materials when exposed to high-pressure gaseous hydrogen. The cornerstone of Sandia’s core capability in hydrogen embrittlement is the Hydrogen Effects on Materials Laboratory where specialized assets reside for conducting mechanical testing of materials with concurrent exposure to gaseous hydrogen at pressures from 1 MPa to greater than 100 MPa.
A national resource for mechanical testing of materials in high-pressure gaseous hydrogen. The laboratory includes a range of specialized assets for evaluating materials performance in high-pressure gaseous hydrogen:
- Thermal Precharging – Materials and test specimens are exposed to high-pressure gaseous hydrogen (up to 140 MPa) at elevated temperature (up to 300 ˚C) before subsequent evaluation.
- Static-load Crack Growth Testing – Instrumented specimens subjected to constant-displacement loading (e.g., wedge-opening load specimens) are exposed to gaseous hydrogen at pressure up to 200 MPa and temperatures over the range of -70 ˚C to 170 ˚C. The material properties measured are the crack velocity and subcritical cracking threshold.
- Dynamic-load Testing – Specimens are exposed to gaseous hydrogen at pressure up to 140 MPa while concurrently subjected to different loading formats, e.g., monotonically increasing or cyclic. Material properties measured include tensile strength and ductility, fatigue strength, fatigue crack growth rates, and subcritical cracking thresholds under rising loading.
Includes several areas of research, including the compatibility of materials and components with high-pressure gaseous hydrogen. The materials and components compatibility program element has several broad objectives:
- optimize the reliability and efficiency of test methods for structural materials and components in hydrogen gas
- generate critical hydrogen compatibility data for structural materials to enable technology deployment,
- create and maintain information resources such as the “Technical Reference for Hydrogen Compatibility of Materials“, and
- demonstrate leadership in the international harmonization of standards for qualifying materials and components for service with high-pressure gaseous hydrogen.
Each of these objectives supports the development, optimization, or implementation of hydrogen containment codes and standards, such as ASME Article KD-10 for stationary and transport vessels, ASME B31.12 for piping and pipelines, CSA HPIT1 for industrial truck fuel systems, SAE J2579 for fuel systems in hydrogen vehicles, and CSA CHMC1 for hydrogen containment material qualification.
This program focuses on the need for safe and reliable hydrogen transport pathways from centralized production facilities, e.g., pipelines. Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines; however, it is well known that these steels are susceptible to hydrogen embrittlement, which compromises the structural integrity of steel components. One manifestation of hydrogen embrittlement in steel hydrogen containment structures subjected to pressure cycling is hydrogen-accelerated fatigue crack growth. Such pressure cycling represents one of the key differences in operating conditions between current hydrogen pipelines and those anticipated in a hydrogen delivery infrastructure. Applying structural integrity models in design codes coupled with measurement of relevant material properties allows quantification of the reliability/integrity of steel hydrogen pipelines subjected to pressure cycling. Furthermore, application of these structural integrity models is aided by the development of physics-based material models, which provide important insights such as the effects of gas impurities (e.g., oxygen) on hydrogen-accelerated fatigue crack growth. Successful implementation of these structural integrity and material models enhances confidence in the design codes and enables decisions about materials selection and operating conditions for reliable and efficient steel hydrogen pipelines.
Summarizes the mechanical properties of materials measured in gaseous hydrogen. This reference is intended to aid engineers of hydrogen systems by providing a compendium of materials properties measured in gaseous hydrogen that can be used in their designs and to aid materials selection for hydrogen service.