A team of U.S. scientists have undertaken a novel study to understand how hydrogen embrittlement causes cracks in 3D printed metal parts.
Southwest Research Institute (SwRI) and University of Texas at San Antonio (UTSA) are working together to understand the susceptibility of Additively Manufactured (AM) materials to hydrogen embrittlement.
Hydrogen embrittlement is a major culprit when it comes to mechanical hardware degrading and materials losing their functionality.
The project led by SwRI’s W. Fassett Hickey and UTSA’s Brendy Rincon Troconis is particularly interested in AM material performance impacting the aerospace and oil and gas industries.
Hydrogen sulfide (H2S) is a gas that is commonly encountered during the drilling of oil and natural gas.
The atomic hydrogen in hydrogen sulfide is liberated and absorbs into the pipeline material and down-hole tools, which leads to degradation in material performance. This is also known as hydrogen embrittlement.
“Atomic hydrogen is an unintended alloying element that can wreak havoc on even the most advanced and modern alloy systems,” says Hickey.
According to the researchers, the project will focus on understanding the mechanisms of hydrogen embrittlement in additively manufactured nickel-based alloy 718.
This will prove useful in the longer run as it could lead to better designed AM parts that are less susceptible or even immune to these dangers.
Hickey and Troconis are working on understanding hydrogen embrittlement at the molecular level to see how the location of the hydrogen atoms affects the integrity of the metal material under the high pressures and elevated temperatures typical of drilling environments.
They hope to accomplish this in SwRI’s unique testing facilities, which allow for mechanical testing in gaseous hydrogen up to 3,000 PSI and 500 degrees Fahrenheit.
UTSA’s thermal desorption spectrometer and scanning kelvin probe force microscope will be used to further understand the hydrogen-alloy interaction and spatially resolve where the hydrogen resides within the alloy microstructure.
Image and content: Protolabs/Southwest Research Institute