Hydrogen-assisted failure in partially recrystallized carbon alloyed equiatomic CoCrFeMnNi high-entropy alloy

We investigated the hydrogen-assisted failure behavior of partially recrystallized carbon alloyed equiatomic CoCrFeMnNi high-entropy alloys. Microstructural evolution in the vicinity of the crack initiation sites and propagation pathways was observed. The results showed that fracture of the samples in the presence of hydrogen was dominated by localized plastic deformation. Hydrogen enhanced nanotwinning and the formation of nanovoids were observed during tensile deformation. Furthermore, stress assisted intergranular and trans granular cracking in hydrogen-charged samples was caused by slip localization at boundaries. Observations confirmed that the resistance to hydrogen embrittlement was increased by the presence of non-recrystallized zones and nanotwins.

Automated summary

In this study, the hydrogen-assisted failure behavior of partially recrystallized carbon alloyed equiatomic CoCrFeMnNi high-entropy alloys was investigated. Microstructural evolution near the crack initiation sites and propagation pathways was observed, showing that fracture of samples in the presence of hydrogen was mainly dominated by localized plastic deformation. The study also revealed the formation of hydrogen-enhanced nanotwinning and nanovoids during tensile deformation, as well as stress assisted intergranular and transgranular cracking in hydrogen-charged samples caused by slip localization at boundaries. The presence of non-recrystallized zones and nanotwins was found to increase the resistance to hydrogen embrittlement.