Rock drill bits have a wide range of uses in geological mining, construction, and other industries, and the market demand is great. Welding predominates in the rock drill bit connection, but there are still a few interference connections and bonding. Compared with the interference connection, welding has the advantages of secure connection, no falling off due to plastic deformation of the matrix, and the large stamina of rock drilling tools. Welding has higher strength than bonding, and the weld is resistant to high temperature and corrosion, so the development and improvement of welding technology are of vital significance to the development of rock drilling tools.
Brazing method of rock drill bit
Brazing methods mainly include furnace brazing, flame brazing, induction brazing, salt bath brazing, laser brazing, and resistance brazing. Induction brazing and flame brazing are the most commonly used in rock drill bit brazing production, and vacuum brazing is used for a few applications. Because of the high cost of vacuum brazing, it is not suitable for mass production. Although the equipment cost of flame brazing is low, it has high requirements on the operator, slow heating, and serious alloy burning loss. Therefore, induction brazing is currently the most used.
The advantage of induction brazing is that it can be heated at a high speed, thereby reducing the degree of metal burning and oxidation, and simplifying post-weld cleaning, causing little warpage and overall deformation, and greatly reducing the softening of the cold-hardened substrate, with relatively low requirements for the operator, and better labor conditions to obtain a clean welded joint. Induction brazing has no restrictions on the shape of rock drill bits, but it is only suitable for small and medium-sized rock drill bits.
Current status of rock drill bit welding technology
At present, rock drill bit welding technology has achieved remarkable development results. Although the traditional welding method meets the connection needs of the drill bit and the drill rod to a certain extent, it still has many shortcomings in terms of welding quality, efficiency, and environmental protection. With the advancement of science and technology and the improvement of engineering needs, new welding technologies have gradually emerged, injecting new vitality into the development of drill bit welding technology.
These new welding technologies have been rapidly adopted and promoted in the field of drill bit welding due to their high precision, efficiency, and low pollution. They significantly enhance the strength and sealing of welded joints, effectively reducing defects such as welding deformation and cracks, thereby improving the drill bits’ overall performance and service life.
Development trend of rock drill bit welding technology
Brazing technology
The development of brazing technology should be compatible with the development of coating carbides, composite carbides, and gradient materials. At the same time, the development of brazing technology should contribute to the research and expansion of the application fields of these materials.
Surface modification technology
The surface wear of the rock drill bit is still quite serious. If a layer of wear-resistant carbide is fused around the rock drill bit, its wear will be greatly reduced.
Rock drill bit materials
The development of low-temperature solder and flux is a direction. Low-temperature brazing is of great importance for reducing thermal stress, preventing surface oxidation, harmful diffusion, and formation of harmful intermediate phases, preventing carbide decomposition, saving energy, and improving labor conditions.
Brazing automation
When the welding batch is large, it is necessary to invest in automated brazing. In the use of automated brazing, manufacturers must solve the manufacturing accuracy of the tooling, the accuracy of the sensor, and timely control, and should also use a small melting interval, good wettability of the solder, and decontamination ability of the flux so that the welding process does not have to move the carbide back and forth to obtain a solid joint.
To develop and improve brazing technology is also to promote the development of brazing methods, processes, and equipment. It helps to prolong the service life of rock drill bits and helps companies to save costs and improve efficiency.
Conclusion
Today, with the rapid advancement of science and technology, drill bit welding technology is a critical link in connecting the core components of drilling tools, and its development trend is moving forward at an unprecedented speed. The deep integration of automation and intelligence will significantly improve the accuracy and efficiency of the welding process and bring revolutionary changes to bit welding. At the same time, the in-depth implementation of the concepts of high efficiency, energy saving, and environmental protection responds to the call for global sustainable development and injects new impetus for green development into drill welding technology. The continuous improvement of welding quality, the widespread application of new materials and processes, and the ongoing innovation and optimization of welding techniques collectively form a grand blueprint for the future development of drill bit welding technology. We have reason to believe that shortly, drill bit welding technology will be more mature, efficient, and environmentally friendly, providing more reliable and efficient solutions for mining, tunneling, and geological exploration and promoting the continuous progress and development of the whole industry.
