Steel bonded carbide tool manufacturing process is different from the ordinary high-speed steel and carbide cutting tools, has a certain particularity, the following elements of the processing.
3.1 Turning
Steel bonded carbide blank hardness 32 ~ 35HRC, carbide ingredients for WC, cutting dosage should go slow small knife volume and greater depth of cut, tool material should be selected YG class grades better to YG8N.
3.2 Milling
High speed steel milling cutter and milling of the drill trench and edge back to the standard type can be used, but the selection of the cutting parameters should be lower than the processing of ordinary high-speed steel drill (about 2/3). The cutting fluid should not be used in the process, because milling produces chips are generally easy paste, mixed with cutting fluid will aggravate the tool wear debris.
3.3 Grinding
Diamond blade grinding steel bonded carbide drill better diamond or silicon carbide grinding wheel, cutting wheel should always be trimmed to keep the grinding wheel edge sharp blade annealing or easy to make, sometimes due to the grinding radial force over large, and even make the tool butt at the break.
3.4 butt
Steel bonded carbide drill head and shank (40Cr) the difference between the thermal conductivity of the material, such as high-speed steel tool butt welding process still can not guarantee the quality of butt, before this butt the 40Cr shank should be first heated , then quickly placed on the welder and steel bonded carbide rods with butt.grinding wheel
3.5 Heat Treatment
The heat treatment of steel bonded carbide drill is an important part of ensuring the quality of the drill bit. Quenching temperature of the tool hardness, such as quenching temperature> 1260 ° C, there will be metal precipitates tool hardness and strength greatly reduced; such as quenching temperature <1180 ° C, it is difficult to guarantee a bit hardness requirements. The test results show that the optimum heat treatment parameters: 1200 1230 ℃ quenching, 560 ° C three times tempering.