The Influence of Ion-Plasma Treatment on Microhardness and Tensile Yield Strength of Austenitic Stainless Steel with Different Grain Size and Microstructure

The effect of ion-plasma treatment (IPT) on tensile yield strength and microhardness in the 316L austenitic stainless steel specimens with gram-subgrained (d<0.5 mu m), tine-grained (d=6 mu m) and coarse-grained (d=55 mu m) structures has been studied. As a result of IPT, the yield strength and microhardness of the specimens increase. The mechanisms responsible for the variation in the yield strength after IPT strongly depend on the initial structural state in steel-density of intergranular boundaries and defects of a crystal structure. The increase in microhardness in the surface layers of the specimens and their yield strength is determined by both solid-solution strengthening and precipitation hardening, regardless of the type of initial structure in them.