Heterogeneous structure parameter effect upon resistance to contact spalling

Abstract

At present time to increase surface layer life in machinery there is formed a heterogeneously streng thened structure representing alternate hard tough areas. The method of static-pulse working (SPW) with surface plastic forming is a method promising enough for the heterogeneous structure formation in a surface layer. At SPW the plastic forming of material to be strengthened is carried out through an impulse load which is a consequence of rise at a blow in an impact system of a strain wave and controlled by the change of geometrical parameters in an impact system. The SPW allows creating a strengthened structure both uniformly, and heterogeneously. For a wider use of the heterogeneous strain strengthening of the SPW in industry there were developed the heterogeneity parameters describing the distribution of hard-tough areas in the surface layer; there were carried out researches of the resistance to a contact spalling of heterogeneously strengthened samples of steel 45, steel X, steel 35 XGSA; there was carried out the analysis of the distribution of hard-tough areas in the surface layer of strengthened samples. As a result of researches carried out for steel 45, steel 40X, steel 35XGSA there was defined a range of heterogeneity parameters conducive to the increase of their resistance to a contact spalling two … six times more.