Scientists have for years been trying to understand how and why steel that is exposed to hydrogen becomes brittle.  But with the help of a custom cryogenic atom probe microscope, the researchers were able to see hydrogen accumulate at grain boundaries. 

The researchers also said they have found the first direct evidence that niobium carbide within steel can trap hydrogen and stop it from migrating to places where its presence would weaken steel.

University of Sydney professor and lead researcher Yi-Sheng Chen said the findings are an important step to developing a steel for equipment that can produce, store and transport hydrogen.

"These findings are vital for designing embrittlement-resistant steel; the carbides offer a solution to ensuring high-strength steels are not prone to early fracture and reduced toughness in the presence of hydrogen," Chen said.

Their findings are reported in the 10 January 2020 issue of Science.