Thermo-deformation treatment (TDT) is a surface-strengthening method that employs concentrated energy sources. In the contact area between the tool and the treated surface, the surface layer of a metal is heated rapidly to reach phase transition temperatures. This heating is followed by a quick cooling process, resulting in the formation of strengthened nanocrystalline layers. Research has demonstrated that a strengthened nanocrystalline layer is formed in the surface layer of cast iron (EN-GJL-200) parts during TDT. This layer has a thickness of 90–120 μm and a microhardness of 7–8 GPa. Near the treated surface, the grain size of the strengthened layer measures 20–40 nm. This strengthened layer significantly enhances the performance of a pair of the “grey cast iron-grey cast iron” during sliding friction with boundary lubrication. In the process of friction with boundary lubrication, when the unit load is increased above 2 MPa, the unstrengthened friction pair works for 2–3 h, and then catastrophic failure begins. Strengthened specimens operate normally when the unit load is increased to 6 MPa. Specimens strengthened using a tool with transverse grooves on the working part have a lower wear rate (by 30–40%) compared to those strengthened using a tool with a smooth work part. Notably, only one component of the friction pair was subjected to strengthening.