Failure form of column tooth drill bit products
among rock drilling tools, the worst service condition is the drill bit product, which has a very short service life. During the working period, the drill bit products not only bear high-frequency impact, but also bear external loads such as torsion, bending, tension and extrusion, and suffer the corrosion of corrosive media such as rock, rock powder and pit water under the conditions of high-speed rotation and collision
the failure forms of column tooth drill bit products mainly include the following forms: broken teeth, broken teeth, tooth removal, drill body fracture, normal wear
1 Broken teeth, broken teeth
the forms of early scrapping of drill bit broken teeth and broken teeth are abnormal failures. The main reasons for their occurrence are as follows:
(1) The rock condition is unclear, the product type selected, the alloy teeth are unreasonable, and the alloy strength is insufficient, resulting in the broken alloy teeth
(2). There are problems in the internal quality of the alloy or the material selection of the alloy is wrong
(3). The quality of alloy products is damaged during processing
(4). The operation method during rock drilling is unscientific, the pressure is too high when drilling, the pumice is pried with a drill bit, and the alloy is blunt and continues to be used
2. The current tooth falling off of the bit alloy
it is abnormal that the tooth falling off of the bit alloy occurs in the early and middle stages, which is mainly caused by the improper selection of the parameters of the tooth fixing process or the processing error of the product in the processing process. In addition, the "empty play" of drill bit products during use can also cause the alloy teeth to fall off
3. Fracture of drill body
the fracture of drill body is mainly fatigue fracture, which is mainly caused by the following factors:
(1) Due to improper material selection of the drill rod, its tensile strength and fatigue strength are low, and it is easy to have the middle and early drill rod fracture that does not help people miss its importance
(2). The geometric structure design of the brazing body that can meet the relevant international standards is unreasonable. There are 10 places where the force is concentrated in the large plastic market, and the R at the transition is increased
(3). The product manufacturing process is improper, the heat treatment of the drill body is insufficient, the hardness of the drill body is insufficient, and the sharp corners and deep tool marks formed by machining are not treated
(4). Unscientific use method, eccentric drilling, blunt drill bit, etc
4. Normal wear
when the drill bit diameter or residual height of alloy teeth reaches or is lower than the rated value, it belongs to normal wear and scrapping, which is the most scientific and our technical pursuit. (end)
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