Influence of the microstructure on the hydrogen uptake and embrittlement of 42CrMo4 steel under gaseous hydrogen charging
Year: 2025
Type: article
Abstract: To determine the microstructural influence on hydrogen uptake and embrittlement behavior, 42CrMo4 was heat-treated to achieve different microstructures with increasing martensite content and tensile strength. Specimens charged at 1000 bar and 25 °C took up between 0.5 and 0.65 wt.-ppm. Charging at 200 °C leads to an increasing hydrogen uptake with increasing material strength and martensite content. Furthermore, CLTs were conducted at the materials yield strength, resulting in a brittle failure of the highest-strength material charged at 1000 bar and 25 °C. To describe the influence of the microstructure on 42CrMo4's embrittlement behavior, in-situ charged SSRTs and the determination of the material's critical hydrogen content were conducted. The critical hydrogen contents are equal to 1.84 wt.-ppm (no martensite), 0.75 wt.-ppm (low martensite content), and 0.23 wt.-ppm (high martensite content), respectively. These results reveal a strongly increasing embrittlement tendency with increasing material strength and martensite content. • An increasing martensite content yields in a decrease in diffusion kinetics. • A maximum hydrogen content of about 0.65 wt.-ppm was achieved by gaseous charging. • The material with the highest martensite content failed brittle in CLTs at YS. • The critical hydrogen contents decrease with increasing martensite content.
Authors: Matthias Eichinger, Dino Zwittnig, Gregor Mori
Institution: Montanuniversität Leoben
Language: English
Subfield: Metals and Alloys
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,730
OpenAlex ID: W4410051795