Finding critical hydrogen concentrations through in-situ hydrogen charging of bearings

Lisa-Marie Weniger

Summary

With the increase in global hydrogen demand and applications, the interest in the effect of hydrogen on rolling element bearings has increased as well. Studies showed that hydrogen embrittlement severely affects 100Cr6 bearing steel, leading to a detrimental decrease of rolling contact fatigue (RCF) life by factors of up to 10 [1–3], which is critical for applications like hydrogen compressors. To identify the effect of hydrogen on bearing steel, both laboratory rolling-sliding tests as well as a novel electrochemical in-situ charging bearing testrig have been employed. The latter allows full thrust bearing tests to be performed under the controlled influence of hydrogen. By combining different tribotesting methods and comparing both electrochemical pre-charging as well as in-situ hydrogen charging while tribotesting, a comprehensive overview of hydrogen embrittlement in rolling element bearings could be gained. One of the key findings of this work is the identification of a critical hydrogen concentration where surface-initiated damage increased significantly.

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