Аннотация:A study and comparative analysis of the physicomechanical properties of surface layers up to 200 nm deep of cast iron alloys A48-30B, 60-40-18 is carried out. A “very hard” phase with the same hardness values has been observed on the surface areas of the two samples under study. The average value of the hardness of the “very hard” area of the 60-40-18 sample is Н60-40-18 = 34.71 ± 12.23 GPa, and that of the A48-30B sample is НA48-30B = 34.57 ± 14.56 GPa. It is found that the average value of the hardness of the A48-30B sample without taking into account the areas with a “very hard” phase is НA48-30B = 8.96 ± 6.93 GPa and it is 65% higher than that of the 60-40-18 sample Н60-40-18 = 5.43 ± 2.57 GPa, also without taking into account the regions with a “very hard” phase. The average value of the index of plasticity of the A48-30B sample without taking into account the “very hard” phase is PIA48-30B = 0.66 ± 0.15 GPa, and that of the 60-40-18 sample is PI60-40-18 = 0.72 ± 0.11 GPa. Thus, the surface of the 60-40-18 cast iron alloy sample is slightly more ductile by 9%. The elastic recovery parameter (EPR) of the A48-30B sample without taking into account the “very hard” phase is ERPA48-30B = 0.23 ± 0.13 GPa, which is more than that of the 60-40-18 sample EPR60-40-18 = 0.17 ± 0.08 GPa.