Hydrogen Embrittlement
Business challenge
Product Innovation
Sector
Hydrogen
Technology or capability
Additive Manufacturing
Experimental Evaluation of Hydrogen Embrittlement Resistance in AM Workhorse Alloys
Introduction
As the hydrogen economy accelerates, industries require robust engineering materials capable of withstanding hydrogen‑rich environments. Hydrogen embrittlement presents a critical challenge—especially for additively manufactured (AM) components whose microstructures and defect profiles differ significantly from their wrought counterparts.
MTC conducted a comprehensive assessment of hydrogen embrittlement behaviour in two widely used AM alloys - 316L stainless steel and Inconel 718 - to provide clarity, confidence and a verified materials knowledge base for industrial members.
Project Challenges
• Hydrogen‑induced failure is a major concern across sectors deploying materials into hydrogen systems.
• AM components lack an established, comprehensive dataset detailing how they behave under hydrogen exposure.
• Unique AM microstructures and manufacturing‑specific defects introduce uncertainty when predicting hydrogen embrittlement performance.
• Industry members expressed a need for clear, standardised guidance on materials selection, testing methodologies and safe deployment of AM components in hydrogen applications.
MTC's Solution
• Conducted an extensive literature review focused specifically on existing hydrogen embrittlement data for additively manufactured materials.
• Carried out surveys across MTC’s industrial membership to identify priority materials, preferred test methods and application‑specific requirements.
• Performed controlled slow‑strain‑rate tensile testing on 316L and IN718, manufactured via LPBF, in high‑pressure hydrogen gas (150 bar) at temperatures from -40°C to +20°C.
• Ensured testing remained compliant with the relevant industrial standards to deliver reliable, comparable results.
• Investigated failure modes and fracture surfaces to reveal the dominant hydrogen embrittlement mechanisms for each alloy.
The Outcome
• Experimental hydrogen embrittlement data was successfully generated for AM 316L and IN718 under critical hydrogen service conditions.
• Mechanisms were identified:
- 316L: Hydrogen‑Enhanced Localised Plasticity (HELP)
- IN718: Hydrogen‑Enhanced Decoherence Embrittlement (HEDE)
• A comprehensive materials database was established, comparing AM and wrought variants across multiple hydrogen exposure conditions.
• Industry members now have access to reliable materials performance data, enabling informed down‑selection for hydrogen applications and improved risk‑mitigation planning.
Benefits to the Client
• Access to verified hydrogen embrittlement data strengthens confidence in deploying AM materials in hydrogen systems.
• Supports compliance with industry standards relating to hydrogen testing and AM materials qualification.
• Enables members to assess AM components manufactured via powder bed fusion for hydrogen applications.
• Provides top‑level guidance on mitigating hydrogen‑induced failures in AM metals, enhancing safety and reliability.
• Establishes a foundation for consistent, standardised testing methodology across multiple sectors.
