With the rapid drilling of hydraulic rock drills, the goal of saving rock drilling auxiliary man-hours and increasing the industrial drilling speed has resulted in the button bit. Its development trend is from the deep well button roller cone bit for oil drilling and the button down-the-hole drill bit for deep hole drilling in mines to a wide variety of button bits. The advantage of the button bit is that the passivation has a long service life. Compared with other drill bits, it has a longer service life and is conducive to reducing the physical labor of workers and speeding up the progress of the project. Even so, in impact rock drilling, it still carries the impact energy transmitted by the rock drill to break the rock, so various failure states will inevitably appear.
15 Ways to Solve the problem of the Failure of Button Bits
1. The solution to the erosion of the bodies due to insufficient slag discharge capacity: Check to ensure that maximum available flushing is employed. If bailing appears to be inadequate, you can try cleaning holes thoroughly after drilling each steel length. Continuing drilling with poor bailing will wear bit bodies excessively.
2. The solution to the erosion of the bodies due to drilling and excessive hole cleaning in loose and fractured material: Don’t use new drill bits in these applications, till the drill bits approach the end of their usable life.Bits with missing buttons unsuitable for regular drilling can still be suitable for soft or broken ground conditions.
3. The solution to the split skirt caused by hammering on a bit to break the connection: Loosen the drill bit while seated firmly on the face or at bottom of the hole.
4. The solution to the steel crack between buttons caused by too big interference between buttons: You need to send it back to the factory for analysis.
5. The solution to the steel crack between buttons socket base due to interference between buttons is too big or no copper shim: You need to send it back to the factory for analysis.
6. The solution to the wring-off bodies caused by the high rotation torque applied to the stuck when it is stuck: you can apply a minimal amount of hammer pressure to the free bit before increasing the rotation pressure.
7. The solution to the lost gauge button caused by dry firing: Don’t engage full percussion unless the bits are seated firmly against solid material. Use reduced percussion when collaring on uneven surfaces if the bits hang up in the hole and when ratting the drill string to loosen connections.
8. The solution to the lost gauge button caused by excessive bit body reduction through erosion from poor flushing or excessive bit body grinding: Ensure the drill cuttings are adequately bailed. Avoid drilling in broken and fractured material where excessive hole cleaning or back drilling is required. Remove only the amount of body required to restore proper button protrusion while grinding.
9. The solution to shattered buttons caused by over drilling: 90% of all button failures are the direct result of continuing to drill with excessive wear flats on the buttons. Remove and service bits once the wear flat on any button reaches 1/3 of the face button diameter. Restore the button profile and protrusion as recommended in the bit sharpening guide before continuing use.
10. The solution to shattered buttons due to forceful rotation in undersize holes, in broken material, or through voids in the rock:
Check that bit diameters are smaller than the hole before attempting to clean or deepen a hole under these conditions. Do not force bits if jamming occurs. Retract until rotation freely then advance slowly with moderate rotation. If this fails, use a scrapped bit or grind down the gauge buttons of the bit to reduce the diameter sufficiently to pass or remove the obstruction.
11. The solution to sheared buttons above or below the bit body caused by forceful rotation against intrusions, in broken material, or through voids in the rock: Jerky rotation and stalling indicate obstructions in the hole. Do not force bits if this occurs. Retract the string until the free rotation is restored. Then advance slowly with moderate rotations until the obstacle is passed or removed. If this fails, you can use scrap bits, a smaller diameter bit, or grind down the gauge buttons of the bit to reduce the diameter sufficiently to pass or remove the obstruction.
12. The solution to sheared buttons above or below the bit body caused by the excessive button protrusion through incorrect sharpening: Protrusions greater than 3/4 of the button diameter will not provide sufficient support to resist the tensile forces that the buttons may encounter.
13. The solution to split buttons due to over drilling: 90% of all button failures are the direct result of continuing to drill with excessive wear flats on the buttons. Remove and service bits on that the wear flat on any button reaches 1/3 of the face button diameter. Restore the button profile and protrusion as recommended in the bit sharpening guide before continuing use.
14. The button solution wears 1/3 diameter due to normal button wear: you need to resharpen the button and restore it to its original profile.
15. When drilling into non-abrasive rock, micro-fractures develop in carbide. The solution to snakeskin, shiny polished appearance is to resharpen bits frequently even if no visible wear is evident.
Precautionary measures
Rock drill bits made of high-quality materials
When selecting a drill bit, we should consider materials with good wear resistance and impact resistance. Different rock types impose varying degrees of wear on the drill bit. Therefore, we should screen the drill bit materials according to the rock types to be drilled. Additionally, for newly purchased bits, we should carry out strict quality inspections to ensure that there are no manufacturing defects.
Reasonable design of drilling parameters
The setting of drilling parameters has a direct impact on the service life of the drill bit. Drilling pressure and rotational speed should be set reasonably based on factors such as rock hardness, drill bit type, and drilling speed to avoid excessive pressure and rotational speed causing excessive wear or breakage of the drill bit.
Reasonable selection and use
According to the specific requirements of the drilling project and the characteristics of the rock, reasonably select the type, specification, and quantity of the button bit. Adhering to proper operating procedures is essential while avoiding practices such as overloading, excessive speed, or prolonged continuous operation can help minimize damage to the drill bit.
Regular inspection of rock drill bits
Regular inspection of the button bit is an important measure to prevent failures. The inspection of rock drill bits includes the wear of the drill bit, the tightening of the connection parts, etc. Once abnormalities are identified, they should be dealt with in time to avoid the expansion of the fault.
Regular maintenance of drilling equipment
The performance stability of drilling equipment is crucial to the normal use of drill bits. Drilling equipment should be maintained regularly, including checking the lubrication system, replacing worn parts, adjusting equipment parameters, etc., to ensure the equipment is in optimal working condition.
Strengthen on-site management and training
Strengthen the management of drilling sites to ensure that operators strictly follow operating procedures. At the same time, regular skills training is provided to operators to improve their operational level and ability to respond to sudden failures.
Things to note
Pay attention to the storage and maintenance of drill bits
During storage, the drill bit should avoid direct sunlight and humid environments to avoid material aging or rusting. At the same time, after each use, the surface of the drill bit should be cleaned of debris and dirt in time to maintain cleanliness and prolong service life.
Pay close attention to abnormal situations during drilling
During drilling operations, it’s crucial to closely monitor factors such as drilling speed, sound, and vibration for any signs of abnormalities. If any irregularities are detected, the operator should stop the machine immediately for inspection to avoid the expansion of the fault.
Follow operating procedures and safety norms
When using button bits, the operator should strictly follow the operating procedures and safety norms to ensure the safety of personnel and equipment. In particular, when replacing drill bits or dealing with faults, the operator should ensure that the equipment is shut down and disconnected from the power supply to avoid accidents.
Record and analyze fault conditions in time
We should record and analyze the causes of the failure problems in a timely manner and summarize the lessons learned. It assists in identifying potential issues and implementing preemptive measures, thereby enhancing troubleshooting efficiency and accuracy.
Conclusion
The structure, parameters, and drilling conditions of the drill bit have decisive significance on the rock drilling speed and the service life of the drill bit. Although we cannot directly observe the specific situation of the drill bit breaking the rock, we can infer that the drill bit drilled the hole based on the conditions such as the drilling progress, the thrust of the rock drill, the hardness of the rock, the failure of the drill bit, and the stripped rock particles. Through the analysis, the manufacturer can improve the material and process of the drill bit to prolong the service life of the drill bit in terms of product quality, thus promoting the development of the industry. The construction party can assist in prolonging the service life of the drill bit from the user specification, thus bringing more economic benefits to the enterprise.
