The article is devoted to the consideration of the method of increasing the mechanical and tribological properties of parts of mining machines due to quenching and electric arc hardening of the restored surface layer by welding. The essence of the proposed method was to restore the geometric dimensions of the part with cored wire with guaranteed hardness of 50-55 HRC and an increase in values up to 60 HRC due to electric arc hardening (EAH), which uses equipment available at each mining enterprise, namely, a tungsten-electrode torch cooled water and protective gas. Argon, which has a relatively low ionization potential, was used as a protective gas, and the use of carbon dioxide was not considered, owing to the increased tendency to crack formation of layers strengthened in this way. The results of studies of the acoustic characteristics of the restored part of the rotation of the welding, made of steel 30HGSA in the initial state of surfacing after electric arc hardening, after quenching and the combined combination of hardening and electric arc hardening are shown.