Hydrogen embrittlement (HE) is a well-known phenomenon that deteriorates the mechanical properties of several metallic materials. Generally, HE susceptibility rises with increasing strength of the material. However, its effect on ductility is worse than on strength. The effects associated with hydrogen embrittlement in metals can lead to catastrophic failures. Nickel martensitic stainless steels (Ni-MSS) are based on the Fe-Cr-Ni-Mo system with low amounts of interstitial atoms, especially C. Due to the good combination of strength considerably higher than austenitic stainless steels (ASS), toughness and corrosion resistance, Ni-MSS are used in applications like oil and gas, aerospace and power generation. In contrast to low strength ASS, there is little research on the influence of hydrogen on mechanical properties of Ni-MSS.
The aim of this work was to study the susceptibility to hydrogen embrittlement of different Ni-MSS, like UNS S17400, S41426 and 1.4418. Thus, slow strain rate tests were conducted after cathodic charging. Additionally, the hydrogen content was measured in uncharged and charged condition aiming to correlate hydrogen content introduced by charging time and hydrogen embrittlement susceptibility. Hydrogen embrittlement of Ni-MSS depends on charging time and hydrogen content. HE has a higher effect on ductility than on strength. It rises with increasing mechanical strength. The microstructure, such as retained austenite and precipitates, also has an influence on the HE susceptibility.
A decarbonized energy system is underway worldwide. The Paris Agreement goal is to keep global warming "below 2 degrees Celsius above preindustrial levels, and to pursue effort to limit the temperature increase even further to 1.5 degrees Celsius."1 To achieve this long-term temperature goal, big changes are needed in the ways energy is produced, distributed and storage. Not only climate change but also petroleum shortages are two reasons to invest in research and development on renewables energies in an efficient and profitable way. In this framework, hydrogen is a central pillar of the energy transformation that can help to develop a sustainable economy. Hydrogen energy demands a huge infrastructure involving hydrogen production, distribution and storage. In this context, stainless steels might play an important part in future energy supply.
