Micromechanical Characteristics of the Surface Layer of Metastable Austenitic Steel after Frictional Treatment

• Published in: Physics of metals and metallography Vol. 122; no. 8; pp. 800 - 806
• Main Authors: Savrai, R. A., Kolobylin, Yu. M., Volkova, E. G.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.08.2021; Springer; Springer Nature B.V
• Subjects: Austenitic stainless steels; Case hardenability; Chemistry and Materials Science; Chromium; Corrosion and anti-corrosives; Corrosion resistance; Corrosion resistant steels; Elastic deformation; Elastic recovery; Hardness; Materials Science; Mechanical properties; Metallic Materials; Microhardness; Modulus of elasticity; Nickel; Probability distribution functions; Strength and Plasticity; Surface layers; microindentation; structure; austenitic corrosion-resistant steel; frictional treatment
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X21080123

The effect of the frictional treatment with a sliding indenter on the micromechanical properties of the austenitic corrosion-resistant chromium–nickel AISI 321 steel (16.80 wt % Cr, 8.44 wt % Ni) has been investigated. The instrumented microindentation results, which was performed on the surface of the steel and at different depths from the surface, has shown the exponential distribution of maximum h max and permanent h p indentation depths, Martens hardness HM , indentation hardness at the maximum load H IT , elastic reverse deformation work of indentation W e , total mechanical work of indentation W t , elastic recovery R е , ratio of indentation hardness to contact elastic modulus Н IT / Е *, power ratio , and plasticity index δ A over the depth of the hardened gradient layer. In this case, the HM , H IT , W e , R е , Н IT / Е *, and values are the highest, whereas the h max , h p , W t , and δ A values are the lowest for the steel surface. The E* contact elastic modulus of AISI 321 steel also increases after the frictional treatment. It is distributed nonmonotonously over the depth of the hardened layer. This can be explained by the formation of different dislocation structures on the steel surface and in the underlying layers. The indentation results have shown that the frictional treatment increases the resistance to mechanical action of both the steel surface and the hardened layer with a depth of to 500 µm.