Abstract:

Drill bit’s wear rate is essential to raise drilling efficiency, increase bit’s service life and decrease the drilling cost. On the base of results of cautiously investigation by scanning electron microscopy (SEM), the authors present a new view on the deterioration and wear mechanisms of cemented carbide rock drill buttons for the DTH hammer drill. The deterioration mechanism includes a composite-scale crack formation, WC grain-scale crack formation, and oxidation and corrosion of WC grains；And wear mechanism includes crushing of WC grains and releasing of fragments, detachment of whole or parts of WC grains, tribo-chemical wear of the carbides. The reason why the buttons on the edge of the bit are worn so terribly is analyzed. The line speed of those buttons is much higher and causes a heavy abrasion which means the WC grains crush terribly. The drilling rate becomes much lower because of a heavy abrasion in large area on the buttons made by the detachment of WC grains； And a reasonable way to maintain the buttons is put forward appropriately.

Key words: SEM, mechanisms, abrasion, deterioration, cemented carbide button, DTH hammer