Abstract: Through analyses of a batch of out-of-work bearings of XHP2S, XHP,
tricone bits，including macroscopic analysis，m etallurgical analysis，iron
spectrum analysis and scanning electron microscope analysis，this paper
points out that' the wear mechanism of bearings of this kind of bit is sep-
arating layer wear，fatigue wear, adhesion wear and grinding wear, etc，
Among them，separating layer wear and fatigue wear are basic ons，whe-
reas adhesion，abrasion, oxidation and corrosion occur at the later period
of wear