EFFECT OF SURFACE MODIFICATION OF 5KHV2S STEEL ON THE MECHANISM AND INTENSITY OF CONTACT WEAR

The paper presents the experimental study of the contact wear of 5KHV2S steel after surface modification. It is shown that without hardening of the surface layer, 5KHV2S steel is capable of satisfactory operation when a pulsat-ing contact stress of 970 MPa is applied. The most qualitative type of surface modification is the hardening of the surface layer by nitrocementation carried out before quenching and tempering. The proposed technology of volu-metric-surface hardening, including forging in a new forging tool, chemical-thermal treatment, quenching and low -temperature tempering, provided the possibility of increasing the pulsating contact stress to 1 100 MPa, and the operation period during the first 13 000 loading cycles gives wear of the working surface no more than 0,1 mm.