Ultrasonic Nanostructuring of Surface Layers of High-Chrome Steels and their Tribotechnical Properties in the Lubricant Media Modified with Ultradispersed Carbon-Containing Additive

Abstract

The influence of ultrasonic treatment of surface layers of steels 40X13 and 12X18H9 on their structure, durometric and tribotechnical properties was studied. It is shown that the ultrasonic treatment of these steels leads to theformation in their surface layer of an ultrafine structure with a subgrain size of ≈25–50 nm and provides an increase in the microhardness of steels by the factor of 2–3. It has been established that addition of ultradisperse carbon-containing additives to the liquid lubricant leads to an acceleration of running of tribo-conjugations, a decrease in the wear rate of 40X13 steel by 60 %, an intensification of the accumulation of crystal lattice defects in materials of a friction pair, and is accompanied with an increase in the microhardness of surface layers and a decrease in their roughness. It has been found that ultrasonic nanostructuring of the surface layer of steel 40X13 leads to an increase in its wear resistance by 20 % with friction in the I-20A lubricant and by 12 % in friction in an I-20A lubricant modified by UDAG particles.

Keywords

• 40x13 and 12x18n9 high-chromium steels
• ultrasonic treatment
• structure
• hardness
• tribotechnical properties