Tungsten Carbide Buttons Used for DTH Drill Mechanism (2/2)

To study the process of tungsten carbide DTH drilling buttons that can be summarized as follows several stages:

Stage I: Cracks emerge, at this stage tungsten carbide buttons just contact with the rock surface, rock stress is transmitted to the contact surface has not been fully released, brittle failure in the contact surface, meanwhile accompanied by the generation of micro-cracks;

Stage II: With the increasing stress, the rock contacted with tungsten carbide button has plastic deformation and forms cracking area;

Stage III: On the boundary of the region will have been pulverized tensile stress cracks, and gradually developed into an initial crack, the crack will be increasing stress and further expansion;

Stage IV: With the increase of stress, both side of the initial crack formation and generates corresponding tensile stress crack, was extended obliquely downward;

Stage V: Cracks form a funnel-shaped expanding and consequential damage leap forward.

In addition, except that the study on the mechanism of tungsten carbide DTH drill buttons, we should also notice that although tungsten carbide buttons have higher hardness and impact resistance, it is brittle and has lower wear resistance. The main pattern of invalid is corrosion, which includes grain wear, surface fatigue wear as well as adhesive wear. It is mainly due to in the process of drilling, the high temperature of the high-speed collision with rock buttons occurrence arising will make carbide hardness decreased and crushed quartz particles made of a soft but opposed the hard phase transition occurs. Therefore, It also put forward tungsten carbide buttons higher requirements, which can be added some element or coated with a high-performance materials to improve the wear resistance of the tooth carbide buttons.

• < Prev
• Next >