Coating technology of tungsten steel Rock Button Bits cutter:
Coating of tungsten steel drill tools. Diamond coated tools have the advantages of high hardness, good wear resistance, and low friction coefficient. At this stage, diamond coating is a good choice for graphite machining tools and can also reflect the superior performance of graphite tools; diamond The advantage of coated cemented carbide cutting tools is the combination of the hardness of diamond and the strength and fracture toughness of cemented carbide. For diamond coating, many coating companies in the world have invested a lot of manpower and material resources to research and develop related Coating technology, but so far, mature and economical coating companies abroad are only limited to Europe;
Tungsten steel drill bit cutting edge strengthening tool cutting edge passivation technology is a very important issue that has not been paid much attention by people. There are microscopic gaps (ie, tiny chipping and sawing) in the cutting edges of carbide tools after the diamond grinding wheel sharpened. The purpose of the tool passivation is to solve the above-mentioned defects of the micro-notch of the tool edge after sharpening, reduce or eliminate the sharp value, and achieve the purpose of smooth and flat, sharp, strong and durable.
The geometric angles of diamond-coated tools and ordinary coated tools are fundamentally different. Therefore, when designing diamond-coated tools, due to the particularity of graphite processing, the geometric angle can be appropriately enlarged, and the cutting groove will also become larger. Reduce the wear resistance of the cutting edge of the tool; for ordinary TiAlN coating, although the wear resistance of the uncoated tool is significantly improved, compared with diamond coating, its geometric angle should be Make it small to increase its wear resistance. PARA, as a graphite processing tool, also uses the world's advanced coating technology for surface treatment of the tool to ensure the machining life and the economical utility of the tool.
Graphite high-speed cutting tool performance and stability put forward high requirements, especially diamond-coated tools are passivated on the edge before coating, in order to ensure the firmness and service life of the coating. However, the domestic diamond coating technology is still in its infancy, and the cost investment is very large, so diamond coating will not have much development in the near future, but we can optimize the angle of the tool on the basis of ordinary tools. , Material selection and other aspects and improving the structure of ordinary coatings, to some extent, can be applied in graphite processing.
In view of the uneven distribution of the contact stress of ordinary floating sleeve bearings, the article proposes three other bus modification curves, including full convex type, modified line type (straight line + intersecting arc), and logarithmic type for the outer and inner edges. . The calculation of the compiled simulation analysis and calculation software shows that the busbar modification has significant significance for improving the contact stress distribution of sliding bearings and increasing the wear life of the bearings. The drill bit is the main tool for oil drilling, and its service life almost directly depends on the service life of the bit bearing. Compared with general mechanical sliding bearings, the Rock Button Bits sliding bearing system is unique in terms of bearing structure, load, bearing working environment and relative speed between sliding pairs.
For a long time, the improvement of the cutting structure has mainly focused on the main cutting tooth structure. In the past ten years, people have gradually realized that the gauge structure also has a greater impact on the drill bit’s ROP and life. Especially the drill bits used in highly deviated wells and horizontal wells require a reasonable gauge structure. Many new gauge structures have been It is researched and developed and applied to Rock Button Bits with good results.
In the 81/2" new high-speed Rock Button Bits design, threaded locking rings and floating sleeve sliding bearings are used, instead of the ball locking devices and sliding bearings commonly used on Rock Button Bits. The threaded locking ring can improve The axial positioning and locking capabilities of the cones greatly reduce the possibility of the cones falling off during high-speed drilling; the use of floating sleeve sliding bearings can reduce the sliding speed of the adjacent two friction surfaces, thereby improving the overall bearing system Speed without loss of load capacity, at the same time it can reduce the friction power loss of the entire bearing system and reduce temperature rise.
Using the theoretical knowledge of finite element, contact mechanics and tribology, combined with the research of other scholars at home and abroad, the force and deformation of the threaded locking ring are studied, and the contact stress and oil film after the outer and inner edges of the floating sleeve bearing are separated are established. Mathematical calculation model for pressure, wear and life prediction. The development trend of drill bits is to achieve high speed, so as an important part of Water Well Drilling Tools, how to improve the service life and working reliability of Water Well Drilling Tools sliding bearings is an urgent problem to be solved at present.