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                  surface layer of the 40X steel with nanocrystalline structure in friction pairs with

                  cast iron ВЧ60 and bronze БРаЖН is provided by mechano-pulse treatment in oil

                  technological medium. High wear resistance remains even after heating to 300 ° C.

                  Wear  resistance of friction  pair  of the  40X steel with  surface nanocrystalline

                  structure  –  cast iron  ВЧ60  in  the corrosive-hydrogenating  medium (diethylene

                  glycol)  is  significantly  higher than  that  of  friction  pair of the  40X steel after

                  quenching and tempering at T = 200 ° C – bronze БРаЖН, which makes cast iron

                  an effective alternative to bronze in friction pairs in diethylene glycol.

                         The  surface nanocrystalline layer  significantly  increases fatigue and

                  corrosion fatigue boundaries, as well as contact fatigue durability of pearlite low-

                  alloyed steels. The usage of mechanical pulse treatment, followed by rolling with

                  rollers to form a surface nanocrystalline structure on the 50ХН and 60Х2М roller

                  steels increases their resistance to fatigue (in 1.4 – 1.6 times) and corrosion-fatigue

                  (in  2.6 – 3.1 times) fracture and  enables achieving  the same level of corrosion-

                  fatigue durability that is inherent to the steel in the as-received state tested in air,

                  that is  completely  offset the  negative  impact of corrosive environment. This

                  increase is achieved by the surface nanocrystalline structure formed in the surface

                  layers, residual compression stresses, and favorable redistribution of the alloying

                  elements.

                         The  applying  of  mechanical  pulse treatment for the formation  of surface

                  nanocrystalline structure on the 60X2M steel in combination with pre-quenching

                  and tempering at T = 450 ° C increases its contact durability and wear resistance

                  by 3.6 and 1.8–2 times, respectively.

                         The surface nanocrystalline layer formed by mechanical pulse treatment at

                  optimal regimes on the 65Г steel increases its contact durability by 1.4 – 2.1 times

                  compared to that of samples after quenching and tempering at 200 ° C; it depends

                  on  the  parameters  of the nanocrystalline structure, namely the size of the

                  crystallites on  the surface,  the thickness  of  the hardened layer and  its

                  microhardness.

                         Nanocrystalline surface  layer formed  by mechano  pulse treatment  on  the
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