Low carbon steel is a kind of material with low hardness and high viscosity, so its cutting performance is poor. In order to achieve the maximum surface roughness of the processed hole after finishing, most of them adopt high speed steel reamer, and use low speed reamer to finish the hole machining by drilling, expanding and reaming. Although such a process can meet the requirements of processing precision, but low production efficiency, short tool life. In the process of ream, before cutting edge reamer blade slightly the devolop, will be the hole wall hair, scratch, which affects the surface quality of hole, in order to solve the common process of these ills, carbide reamer hole on finishing high-speed ream experiment was carried out, obtained satisfactory results. The cutting principle of high speed steel reamer and carbide reamer is different, high speed steel reamer relies mainly on the cutting edge sharp to obtain lower surface roughness value, and the carbide reamer is heavily dependent on squeeze cut to obtain lower surface roughness value, so the tool geometric angles are different requirements and cemented carbide reamer.

According to the cutting principle, it is required to cut the sharp edge of low carbon steel reamer which is sticky and soft. The blade material has a direct influence on the tool life. After the reamer is made from five different materials of YT15, YA6, YW1, YT5 and YW2, the effect is also different. Made reamer, YT15 material out of the hole surface roughness value is low, but in the process of cutting edge area easy caving, YT5 and YA6 material made ofcemented carbidereamer, surface roughness value after the ream, but quick wear of cutter relative to other blade material, low service life. For the reamer of YW1 material, the surface roughness value Ra= 1.6m after the reamer is hinged. However, due to the low flexural strength of the blade, blade breakage often occurs. Compared with the reamer of the above brands, the reamer made by YW2 has low surface roughness value and high tool life when processing low-carbon steel.

Improvement of tool structure. In order to overcome the soft hardness and high stickiness of low carbon steel, the head of the reamer is designed and made into a guide head with a certain Angle. This kind of guide head can not only guide the cutting edge of the tool during cutting, but also make the hole machining more linear. In addition, the residual chip can be pushed out to the front of the hole, which will not make it difficult to discharge the chip. The chip is squeezed into the slot of the reamer, resulting in more chip accumulation and tearing the hole wall, damaging the surface quality of the hole. Cutting tool structure adopted large blade Angle, not only can make the reamer smooth cut, and chip can discharge smoothly, at the same time in order to make the chip has enough capacity space, so the standard reamer to decrease the number of. Whether the machining process is properly prepared or not will directly affect the cutting effect. When cutting low carbon steel, the original drilling, expansion and hinge three processes can be changed into drilling and hinge two processes. Due to the nature of the carbide reamer ream is crowded cut, so it is very important to remain ream cushion before ream, function under ream leave allowance is too small, there wasn't enough margin to cause ream, may lead to the surface of the hole is too big and leave the walls drilling trace; If the residual amount is too large, the cutting resistance will be increased and the tool bar will be distorted. Meanwhile, the tool life will also be significantly reduced, and even a large number of chips will be generated and the surface of the hole will be damaged.

Choice of rational cutting allowance to ream holes has a great impact on the quality of low carbon steel material, usingcemented carbidereamer hole for low-speed ream can obtain lower surface roughness value, but the low cutting efficiency; However, the use of moderate speed cutting is easy to produce chip deposition, which affects the surface quality of the hole. High speed cutting is relatively ideal, can greatly improve the productivity, but also can obtain good machining quality, if match with suitable cutting fluid, the cutting tool can improve the life (in extreme pressure cutting fluid is preferred).

Related link:

http://www.wococarbide.com/Transaction/en_information.html

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