3D Printed hydrogen resistant alloys: Unlocking the evolution of hydrogen energy in Qatar (ProgRess-H2Q)

Hydrogen embrittlement (HE) is a long-standing challenge for the Oil and Gas industry in Qatar and internationally. It is becoming increasingly important when the whole petroleum sector faces the aging infrastructure and has to develop an appropriate life extension strategy. When exposed to seawater, subsea components are usually connected to a cathodic protection (CP) system to prevent corrosion. A by-product of this system is atomic hydrogen generated at the surface, which is absorbed and diffuses into the metal and causes material degradation (i.e., hydrogen embrittlement) that may lead to premature failure with catastrophic consequences. On the other hand, by the emergence of hydrogen as an energy carrier holding a key role in the inevitable and needed transition from fossil fuels to renewable energy, together with Qatar's important role as a major energy provider in the world comes the obligation to be a leading player in this transition. Hydrogen has the potential to both act as an energy buffer for intermittent and weather-dependent renewable sources, as well as carrying the energy stored in fossil fuels in a carbon-neutral way if done with Carbon Capture and Storage (CCS). However, hydrogen embrittlement (HE) is shown to be one of the main bottlenecks in establishing reliable and safe structures for storage and transporting hydrogen. Traditionally, nickel-based corrosion-resistant alloys (CRA) are believed to be immune to HE. However, longtime exposures and different incidents, especially in the oil and gas industry, revealed that still, we need to understand a lot about the HE in this class of alloys. Most of the research shows that the small variations in the processing and heat treatment of the Ni-base alloys can result in changes in their resistance to hydrogen embrittlement. For example, the formation of grain boundary precipitates during the hardening heat treatment can diversely affect the hydrogen embrittlement resistance of alloy 725. Recent advances in additive manufacturing and 3D printing provide a great advantage in manufacturing the critical components with Ni alloys for different sectors, including the energy sector. Aside from the versatility in designing components, 3D printing, and additive manufacturing provide new possibilities towards reducing the carbon footprint and cost reduction. For example, new concepts of industry 4.0, such as digital warehouse, can eliminate the shutdown times through the implementation of additive manufacturing by reducing the delay in providing spare parts. Also, through controlling the 3D printing parameter, it is possible to control the resulting microstructure and the expected properties of the final component [1]. While there has been a large amount of research focusing on optimizing the mechanical properties of 3D printed Ni alloys, there is very limited work on the hydrogen embrittlement of these alloys [2]. Most of the research shows that the small variations in the processing and heat treatment of the Ni-base alloys can result in changes in their resistance to hydrogen embrittlement. For example, the formation of grain boundary precipitates during the hardening heat treatment. In this project, we propose to develop 3D printed Ni-based CRA, which are highly resistant to HE for application in both Oil and Gas as well as hydrogen energy and transportation. We will study the hydrogen trapping and diffusion coupled with mechanical loading in these alloys as a function of 3D printing strategy and parameter for selected compositions. Using a recursive approach and using our understanding from diffusion and trapping in these alloys, we will develop 3D printing strategies to develop the next-generation hydrogen-resistant alloys. The project will be divided into five interacting work packages (WP) looking into 3D printing, Characterization, Mechanical testing, and Computational modeling and analysis.

Hamad Bin Khalifa University (HBKU)