冲击载荷作用下锥形截齿磨损的试验和数值模拟研究

Tests and simulation for wear of conical pick under impact load

通过试验和离散元数值模拟方法,研究锥形截齿的耐磨性能及其磨损特征对截割载荷的影响。在单齿旋转截割试验台上,以砂岩为试验对象,采用3种不同齿尖材料的锥形截齿进行岩石截割试验,并结合试验后齿尖的磨损面形状建立磨损截齿模型,利用PFC^(3D)进行岩石截割的数值模拟研究。统计结果表明:在截割载荷各分量中,法向力显著高于切向力和侧向力;硬质合金截齿、合金钢截齿及有耐磨涂层的合金钢截齿的质量损失依次为0.07%,0.28%和0.22%,硬质合金耐磨性优势突出,堆焊耐磨涂层对截齿有一定的保护作用;齿尖磨损区域的扩展,使截齿连续过载,加剧磨损;通过离散元方法获得的截割载荷与试验方法测定结果接近。在相同截割条件下,对硬质合金和合金钢齿尖耐磨性能的研究,为截齿的寿命估计提供必要参考。

The effects of wear resistance of conical pick and its wear characteristics on cutting force were studied with tests and simulation. On a rotary cutting test table with a single pick,sandstone cutting tests were performed by using three types of conical pick made of different pick-tip materials. The wear pick model was built according to the wear surface shape of pick tip,and the numerical simulation of rock cutting was studied with PFC^（3D）software. Statistical results showed that the normal force is significantly higher than the tangential force and lateral force in components of cutting force; the mass loss of cemented carbide pick,alloy steel pick and alloy steel pick coated with wear resistance material are0. 07%,0. 28% and 0. 22%,respectively; using cemented carbide as pick tip material has excellent wear resistance,and surface welding with wear-resistant coating on pick has a protective effect; an expanded wear surface of pick tip causes a heavy load acting on pick continuously to aggravate pick wear; cutting forces obtained with the discrete element method agree well with relevant test results. Under the same cutting conditions,the study results of wear resistance of pick tip made of cemented carbide and alloy steel provided a necessary reference for pick life evaluation.