Effect of titanium concentration on the structural-phase state of the surface layer of carbon steel alloyed under the action of compression plasma flows

Abstract

The effect of the concentration of an alloying metal on the structural-phase state and microhardness of the surface layer of St3 carbon steel alloyed with titanium and nitrogen under the action of compression plasma flows on the Ti-steel system is studied. The fraction of titanium is increased from 3 to 33 at % by two techniques: multiple repetitions of the processes of titanium coating deposition and compression plasma processing or the thickening of the alloying metal coating. It is found that the phase composition of the mixed layer with a thickness of 4–10 μm depends on the alloying element concentration and can contain both the α-Fe based supersaturated solid solution and the intermetallide Fe2Ti as well as the nitride TiN. The structural-phase transformations cause a two- to threefold increase in the microhardness of the steel.