A new delamination pattern in elevated-temperature oxidative wear

The sliding wear tests were performed under the atmospheric conditions at 400 °C for H13 steel. The effects of load on the wear mechanisms and delamination patterns were studied. A new delamination pattern was found to appear in the mild-severe transition region of the elevated-temperature wear. The delamination pattern could be proved by the belt-like debris and the corresponding wide ditches on worn surfaces. Under the loads of 50–100 N, mild oxidative wear prevailed with the characteristics of the plate-like oxide debris and low wear loss and its delamination was from inside oxides or the interface between the oxides and bulk metal. The wear rate increased with increasing load; the mild–severe wear transitions occurred under the loads of 100–200 N concomitant with more and more belt-like debris and wide ditches on worn surfaces. In this case, the wear loss would be mainly attributed to a special delamination from inside the bulk metal underneath the tribo-oxides with the formation of belt-like debris containing oxide and bulk metal. The delamination pattern was realized by the way that the ploughed furrows were first formed by the micro-cutting of oxide particles in the delaminated zone, whereby cracks initiate from the furrow wall and propagate parallel to worn surface to cause the delamination.