Susceptibility of nitrided layer mechanical properties in AISI 4140 steel as a response to hydrogen embrittlement

Abstract In the present research, the mechanical behavior and susceptibility to hydrogen embrittlement are studied in AISI 4140 steel samples subjected to a heat treatment of quenching and tempering, followed by a thermochemical treatment of nitriding using times of 12 and 60 h. To evaluate the effects of these processes, the samples were subjected to cathode charge tests for 25 h. Tests and characterization techniques for results included bending, microhardness, x-ray diffraction (XRD) and scanning electron microscopy (SEM) tests. The results obtained provided a comprehensive view of the impact of the treatments on the mechanical properties and susceptibility to hydrogen embrittlement in this type of steel, contributing to the understanding of its behavior in critical applications.