In working environments such as quarries, high-pressure DTH drill bits are critical tools, and their stability and durability are directly related to production efficiency and cost. However, DTH drill bits often encounter failure problems, such as end face cracking and alloy tooth fracture. These problems affect the operation’s progress and may also bring safety hazards. This article will analyze the reasons for the failure of high-pressure DTH drill bits and provide corresponding solutions to help customers better understand and maintain the drill bits to ensure smooth production.
What is a high-pressure DTH drill bit?
A high-pressure DTH drill bit is a tool that uses high-pressure gas (usually compressed air) as a power source for rock or ore drilling operations. The difference between it and medium and low-pressure DTH drill bits is the specifications and models of the matching DTH hammers, and there are significant structural differences.
Analysis of failure causes of high-pressure DTH drill bits
End face cracking
Reason : High carbon content of material
One of the main reasons for drill bit end-face cracking is the high carbon content of the button material. Although high-carbon alloy steel increases the strength and hardness of the material, it significantly reduces the material toughness. Under high-frequency impacts and extrusions, the surface tissue of the end face is prone to severe deformation and extrusion hardening, eventually leading to cracking between the two places.
Solution:
Adjust the material composition: reduce the carbon content of the tooth material to ensure that the material maintains sufficient strength while increasing its toughness and reducing cracking caused by deformation hardening.
Optimize the heat treatment process: improve the material’s organization and properties through reasonable heat treatment processes, such as quenching and tempering, to increase its resistance to cracking.
Reason 1: The sintering temperature is too high
During the sintering process of the cemented carbide button, if the temperature is too high, the coarse interface will oxidize and form a brittle η phase. This brittle phase not only reduces the strength and toughness of the material but also tends to become a channel for crack expansion, eventually leading to the fracture of the carbide button.
Solution:
Strictly control the sintering temperature: ensure that the sintering process is carried out within the specified temperature range to avoid interface oxidation and brittle phase formation caused by excessive temperature.
Optimize the sintering process: use advanced sintering technology and equipment, such as vacuum sintering or atmosphere protection sintering, to reduce oxygen contact and prevent oxidation reactions.
Reason 2: Too fast cooling rate
Excessive cooling rate after sintering will also cause the hardness of the carbide button to be too high, while the flexural strength and impact toughness are reduced. Under high-speed impact and extrusion, carbide buttons are more likely to break.
Solution:
Adjust the cooling rate: use a reasonable cooling process, such as isothermal quenching or graded quenching, to slow down the cooling rate to avoid excessive hardness and reduced toughness.
Strengthen quality inspection: a strict quality inspection is carried out on the sintered carbide button, including testing the hardness, bending strength, and impact toughness to ensure the product performance meets the requirements.
Other solutions
Material R&D and upgrading
In response to the failure problem of high-pressure DTH drill bits, material R&D and upgrading should be carried out continuously. By adjusting and optimizing the material’s chemical composition and heat treatment process, the comprehensive performance of the material, especially the balance of strength and toughness, can be improved. At the same time, new materials, such as high-strength low-carbide steel and new cemented carbide, should be developed to meet more demanding operational requirements.
Manufacturing process optimization
Optimizing the manufacturing process is the key to improving the durability of the drill bit. From raw material selection and processing process control to finished product testing, every link should be carried out strictly by the specifications. Use advanced processing equipment and testing technology to ensure stable and reliable product quality. At the same time, enhance employee training to improve operating skills and quality awareness.
Regular inspection
Regular inspection of high-pressure DTH drill bits is essential for preventing failures. The inspection should include checking for wear and cracks in the drill bit. If any problem is detected, we should deal with it in time to avoid the expansion of the problem. Additionally, it’s pivotal to maintain a usage log for rock drilling tools, recording their usage to provide a basis for future fault analysis and improvements.
Conclusion
The failure of high-pressure DTH drill bits is a problem that cannot be neglected in operating environments such as quarries. By analyzing the causes of failure, we can take targeted solutions, such as optimizing material composition, strictly controlling the sintering process, strengthening daily inspections, and improving operator skills, which can significantly improve the durability and stability of the drill bit, reduce production costs and safety hazards, and provide strong guarantees for the production of quarries. At the same time, this also requires the joint efforts and cooperation of quarries, equipment manufacturers, and scientific research institutions. We believe that with ongoing technological advancements and innovations, the issue of high-pressure DTH drill bit failures in quarries will be more effectively addressed.
