冲击回转钻进条件下硬质合金钻头柱齿磨损机理

Wear Mechanism of the Rock Drill Buttons in the DTH Hammer Drill

减缓钻头硬质合金柱齿的磨损速度,对提高钻头工作效率、延长钻头使用寿命、降低钻进成本等具有重要意义。在利用扫描电子显微镜(SEM)对钻头柱齿详细观测的基础上,提出了风动潜孔锤钻头硬质合金柱齿新的劣化机理和磨损机理:劣化机理包括混合规模裂隙的形成、WC颗粒规模裂隙形成和WC颗粒的氧化和腐蚀;磨损机理包括WC颗粒的破碎和碎片释放、整体或部分WC颗粒的脱离、碳化物的摩擦化学磨损等。分析了边齿因回转线速度大,磨损也增大,WC颗粒的破碎和碎片释放量增大而磨耗严重的机理;因WC颗粒的整体脱离使柱齿产生较大面积的磨损,导致钻进效率的大幅度降低;给出了钻头柱齿必须及时加以修磨的合理使用方法。

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.