During the drilling process, the chipping or wear of carbide roller drill bits is a common problem. Timely and effective repair measures can not only extend the service life of the drill bit, but also ensure the drilling efficiency and safety. According to different damage degrees and types, it is necessary to select appropriate repair methods based on actual conditions, and pay attention to performance evaluation and maintenance after repair.
When carbide roller drill bits are slightly worn, they can be repaired by grinding and polishing. By using special grinding tools and abrasives, the surface of the worn part is finely polished to remove burrs and uneven areas caused by friction, and the sharpness of the drill bit cutting edge is restored. This method is suitable for the situation where the drill bit edge is only slightly blunted or partially worn. The operation is relatively simple and can quickly restore its basic cutting performance without affecting the overall structure of the drill bit. During the grinding process, it is necessary to pay attention to controlling the strength and direction to avoid secondary damage to the unworn parts. At the same time, it is necessary to ensure that the angle of the grinding edge meets the design requirements to ensure the rock breaking efficiency during drilling.
For the situation where the chipping area is small or there is a gap locally, brazing repair is an effective means. First, the chipped edge part needs to be cleaned to remove the oil, oxides and other impurities on the surface to ensure that the welding interface is clean and flat. Then select a brazing material that matches the composition of the cemented carbide, melt the brazing material by heating and fill it into the chipped edge notch to achieve metallurgical bonding between the cemented carbide and the brazing material. During the brazing process, the heating temperature and time must be strictly controlled to avoid changes in the internal structure of the cemented carbide due to excessive temperature, which will affect its mechanical properties. After the repair is completed, the welding part needs to be polished and trimmed to make the drill surface smooth and flat, and restore the original geometric shape and dimensional accuracy.
When the wear or chipping is more serious and exceeds the scope of local repair, laser cladding technology may be required for repair. Laser cladding uses a high-energy-density laser beam to quickly melt and clad alloy powder of a specific composition on the damaged part of the drill bit to form a cladding layer that is firmly bonded to the substrate. This method can accurately control the thickness and composition of the cladding layer according to the damage of the drill bit. It can not only repair the worn or chipped edge part, but also further improve the wear resistance and impact resistance of the drill bit surface by adding high-performance alloy powder. Laser cladding has the advantages of small heat-affected zone, low deformation, and high repair efficiency. It is suitable for repairing carbide roller drill bits with high precision requirements, but the equipment cost is high and requires professional technicians to operate.
For some drill bits with complex structures or severe damage, if the above repair methods are difficult to work, partial replacement of parts can be considered. For example, when a roller of a roller drill bit is severely worn or cracked, the roller can be removed and replaced with a new roller of the same specification. During the replacement process, it is necessary to ensure that the connection between the new roller and the drill bit base is firm and reliable, such as using high-strength bolts or welding to fix it. After the replacement is completed, the assembly accuracy of the entire drill bit should be checked to ensure that the matching clearance between the components meets the requirements to avoid new problems in the drilling process due to improper assembly.
Repaired carbide roller drill bits need to undergo strict performance testing and quality inspection. First, the appearance of the repaired part should be checked to see if the surface is smooth and there are defects such as cracks and pores; then, through hardness testing, wear resistance testing and other means, evaluate whether the mechanical properties of the repaired part meet the use requirements. In addition, it is necessary to conduct simulated drilling tests, observe the operating status of the drill bit under different working conditions, detect its rock breaking efficiency, drilling stability and other indicators, and ensure that the repaired drill bit can meet the needs of actual drilling work. If the repair effect is found to be unsatisfactory, it is necessary to analyze the cause and reselect the appropriate repair method for treatment.
In order to reduce the frequency of chipping and wear of carbide roller drill bits, preventive measures should be taken in daily use. Reasonably select the drill bit model and specifications to match the drilling formation conditions and equipment power parameters; strictly follow the operating procedures for drilling operations to avoid excessive impact loads or torque on the drill bit due to improper operation; regularly inspect and maintain the drill bit, clean the rock chips and impurities on the surface of the drill bit in time, observe the wear and keep records, so as to repair it in time at the early stage of damage. At the same time, strengthen the training of drilling operators, improve their understanding of drill bit performance and maintenance knowledge, enhance their operating skills and sense of responsibility, and reduce the risk of drill bit damage from the source.
Repairing the chipping and wear of carbide roller drill bits during drilling is a highly technical job. It is necessary to select the appropriate repair method according to the degree of damage, the structural characteristics of the drill bit and the actual use requirements, and to carry out inspection and daily preventive maintenance after the repair. Through scientific and reasonable repair and maintenance, it can not only extend the service life of the drill bit and reduce drilling costs, but also ensure the efficient and safe progress of drilling work, providing strong support for various engineering construction.
