Twist drills are one of the tools that consume the most. The semi-closed cutting environment and special geometrical structure make the drilling temperature higher than the turning and milling temperature under the same conditions, plus the cutting speed and geometric parameters of the cutting edge will change, resulting in the service life of the twist drill. Far lower than other tools, it is difficult to adapt to the trend of high-speed machine tools and high hardness of processed materials. For this reason, the normal and magnetized twist drills were selected for the drilling test under the same conditions, and the cutting performance of the drill was expressed in terms of the maximum number of drillable holes. Based on this, the service life of the magnetized treatment was studied. influences. 1 Test conditions and methods Drilling materials: common sheet, Q235, plate thickness 10mm. Bit parameters: ordinary twist drill, material HSS, diameter 9.8mm. Machine type: bench drill, model Z512B, speed 800r/min, manual feed control, coolant 5% emulsion. During the test, a batch of purchased twist drills was divided into 4 groups, in which the first group remained as it was without any treatment and the number was 20: the second group was magnetized so that the cutting part of the drill bit was N pole and the drill shank end was S. The number of poles is 30: The third group is also magnetized so that the cutting end of the drill is S pole and the shank end is N pole, the number is 30: The 4th group is demagnetized after magnetization treatment, the number is 20 . The magnetized drill bit is placed end to end with N and S poles to avoid degaussing and affect the test results. The test method is to drill holes in the sheet until the drill bit emits a certain noise, the bluntness is severe and the cutting action fails, or the cutting part is damaged and cannot be cut, and the number of drillable holes is recorded one by one. 2 Test results Twist drill test results for Group 1 without any treatment (20 test points): 2234 holes in total, approximately 111 holes per hole drilled: Group 2 was magnetized and drill bit was N pole Test results (30 test points): Total number of holes drilled is 4,596 holes, with an average of approximately 153 drill holes per hole: The third group is magnetized and the drill bit is the S pole test result (30 test points): Total drilling Number of 4461 holes, with an average of approximately 148 holes drilled per hole: Test results of demagnetization of the fourth group after magnetization treatment (20 test points): The total number of holes is 2,239 holes, with an average of approximately 119 holes per hole. 3 Analysis of the results After comparing the data of the first group and the second and third groups, it was found that after the magnetization treatment, the average drillable number of the drill bit was increased from 111 holes to 153 holes and 148 holes, and the average number of drillable holes was 151 holes. Increased by 35.2%. It can be seen that after the twist drill has been magnetized, the service life of the drill bit can be significantly improved. Comparing the data of the second group and the third group, it was found that the same drilled magnetized drills also had different drilling abilities. The number of drilled holes for the N-pole twist drill was more than that of the drill bit for the S-pole. The twist drill with N-pole drill has long service life and better performance. Comparing the data of the first group and the fourth group, it was found that demagnetization was performed after the magnetization treatment, and the number of drillable holes did not change much. It can be seen that the demagnetization after magnetization has little effect on the service life of the drill bit. In addition, through the analysis of the cutting part of the magnetized twist drill, it is found that the probability of failure due to chipping after magnetization is much lower than that of the twist drill without magnetization, and after the magnetization treatment, the HSS can be changed. The internal atomic arrangement can effectively protect the drill bit from local damage due to impact, friction, and the like. 4 Conclusion Magnetization can significantly increase the service life of high-speed steel twist drills. The cutting part of the drill is an N-polarized magnetizing treatment, and its service life is better than the magnetized treatment of the S-pole in the cutting part of the drill. Twist drills are magnetized and demagnetized, and their service life is not changed much.
Carbon Steel Coil
Continuous casting slabs or primary rolling slabs are used as raw materials, heated by a stepping furnace, and dephosphorized by high-pressure water, and then enter the roughing mill. The rough rolling material is cut through the head, tail, and then into the finishing mill, and computer-controlled rolling is carried out. After the final rolling, it will go through laminar cooling (computer-controlled cooling rate) and take-up by the coiler to become a straight hair coil. The head and tail of straight hair curls tend to be tongue-shaped and fish-tailed, with poor thickness and width accuracy, and often have wavy, folded, tower-shaped and other defects on the edges. The coil is heavier and the inner diameter of the steel coil is 760mm. (Generally used in the pipe-making industry.) After straightening the hair through the cutting head, tail cutting, trimming and multi-pass straightening and smoothing finishing lines, and then cutting or re-rolling, it becomes: hot rolling steel plates, flat hot rolled steel coils, slitting tapes and other products. If the hot-rolled finishing coil is pickled to remove scale and coated with oil, it will become a hot-rolled pickled coil.
HRC Steel Coil,Cold Rolled Steel Coil,Hot Rolled Steel Coil,Hot Rolled Steel Coils
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