Effect of the Conditions of the Nanostructuring Frictional Treatment Process on the Structural and Phase States and the Strengthening of Metastable Austenitic Steel

Increasing the micromechanical and tribological characteristics of an austenitic steel by surface deformation processing

“…As a result of FT, the microhardness on the surface of the 03Cr16Ni14Mo3Ti steel increases from 270 HV 0.025 to 720 HV 0.025. According to [1,2], with FT, the hardening of the surface of the metastable 12Cr18Ni10Ti steel with an initial hardness of 220 HV 0.025 reaches 710 HV 0.025 despite increased loading (P=392 N) and the number of scans (n=11). Consequently, FT provides the 03Cr16Ni14Mo3Ti steel with strain hardening not inferior to that of the metastable 12Cr18Ni10Ti steel, whose surface acquires 70 vol% of strain-induced α´-martensite after FT.…”

“…Nanostructuring FT with a sliding indenter is an effective method for improving the strength and tribological properties of Cr-Ni metastable austenitic steels with 8.44 to 10.04% Ni [1][2][3]. It is of interest to discuss the features of FT of austenitic steel with a high nickel content (14.17%), which makes austenite resistant to the strain-induced γ→α' transformation, since the presence of strain-induced martensite in the surface layer may have an unfavorable effect on the corrosive characteristics of the steel [4].…”

Effect of frictional treatment on the microstructure and surface properties of low-carbon steel

“…For a carbon steel subjected to frictional treatment, the decrease in the elastic modulus is observed for the first time. It was previously observed that the frictional treatment under certain conditions decreases the contact elastic modulus E * of austenitic stainless steel, however, the decrease is less than 8 % [14]. Besides, parameters characterizing the ability of the surface to resist mechanical contact action, which are presented in Table 2, have been determined from the characteristics measured during indentation.…”

Nanostructuring and surface hardening of structural steels by ultrasonic impact-frictional treatment

“…Such promising methods for surface nanostructuring of metal materials as frictional treatment by a sliding indenter [1,2] and ultrasonic treatment with a vibrating tool [3][4][5] have a high potential of practical applications. The most important factors of effective nanostructuring and strain hardening of a surface layer are as follows: 1) normal load sufficient for the formation a new rough surface, as well as multiplicity of the deformation effect for the accumulation of strain [6,7]; 2) inhomogeneous shear deformation with a sharp gradient [8]; 3) a high friction coefficient to enhance shear deformation [9,10]; 4) noncorrosive environment to prevent embrittlement by atmospheric oxygen followed by the failure of the diffusely active nanostructured layer [11]. These factors govern the conditions for the implementation of the rotational mechanism of plastic deformation, which is responsible for the nanostructuring of metallic materials.…”