EFFECT OF DIFFRENT LOADS ON THE WEAR BEHAVIORS OF 5Cr5Mo2V STEEL AT 700 °C

Abstract

The effect of different loads on the high-temperature wear behavior of 5Cr5Mo2V steel at 700 °C was investigated. Wear morphologies, oxide compositions and matrix evolution were studied. The results showed that the wear rate increased with an increased test load, and the wear mechanism transformed from abrasive-oxidative wear to adhesive-oxidative wear. The relation between a delaminated oxide layer and cracks in the matrix were investigated. The exfoliation of carbides and displacement difference between the matrix and carbides caused a crack initiation. The wear rate strongly related to carbides, and coarse M6C carbides with poor holding power led to a high wear rate. Besides, a diagram of wear characteristics under different loads was suggested in this work.

Wear characteristics of austenitic steel and martensitic steel at high temperature

“…The plastic deformation of subsurface contributed to the formation of tribological layer, the wear behaviour was affected by oxides and subsurface deformation [15]. It is generally accepted that wear resistance of the different microstructures depends on thermal stability, toughness and plastic deformation resistance, especially the microstructure change and energy consumption during sliding [16][17][18]. By comparing the wear characteristics of austenitic stainless steel and austenitic-ferritic stainless steel, Straffelini [15] found that the low ductility can delay wear transformation (delamination→tribo-oxidation) in austenitic-ferritic stainless steel.…”