Physical Properties Of Carbon Drill Bit

     High speed steel twist bit and common steel handle, is dissimilar material welding, its main difficulty is the chemical composition of two kinds of materials, different mechanical properties, in the weld area easily produce cracks, after testing, take some necessary measures, can be successfully welded. Carefully remove the solder joints and the surrounding oil, rust, oxides, etc. until the pure metal is exposed. Grinding the joint with a grinding wheel into a 60-70 degree x symmetrical groove, leaving the blunt edge 2-3 mm, clearance 1.5-2 mm.Carbon Drill Bit
     Electrode selected J506 or J422, after 200 ℃ drying, insulation 1-2 hours. According to the situation, consider preheating before soldering, using oxy-acetylene flame, heating the end of the bit to 450-500 ℃. In the high-speed steel twist drill part, in addition to the welding place all the asbestos, immersed in the oil basin, can be vertical, also can be inclined to put, oil basin should be stamped iron plate to prevent the droplet splash into the oil, causing grease splash. DC power supply Reverse or AC welding power supply can be. The use of thin electrode, small current, at the end of the bit surfacing a thin layer as a transition layer, the angle should be as small as possible to prevent the mother metal too much melt into the weld.Carbon Drill Bit
     The welding of the transition layer of welding and carbon steel welded pieces of the fixture fixed, straight, and then along the circumference of every 90 degrees of positioning welding, ARC-biased carbon steel side, as far as possible to reduce the high speed steel side of the deep penetration. The use of symmetrical and short welding path welding, attention, in the case of penetration, welding should be thin, small diameter electrode, small current welding, generally speaking, the electrode diameter of 3.2 mm, welding current 80-100a, electrode diameter of 2.5 mm in 60-80a. The angle of the strip, should be appropriate, the arc should point to the carbon steel side, and the drill part of the axis of the angle of 25-35 degrees, and circumferential tangent 35-40 degrees angle.Carbon Drill Bit
    With low heat temperature welding, control the melting temperature of joints, welding electrodes should be stable and uniform movement, when the arc should be back to fill the arc pits, welding this weld, the total arc should be less than 1/3 of the welding carbon steel. After welding the Red hot state, quickly put the workpiece on the machine, slowly drilling in advance fixed on the workbench with the drill bit size similar to the steel, so that straightening, straightening process temperature should be higher than 400 ℃. During the welding process, if the cutting edge of the bit reaches the annealing temperature, the heat treatment should be carried out according to the standard of the twist bit. On the cutting edge of the workpiece is not heated, after the welding will be immersed in the oil inside the turn, the joint part with asbestos bag, thermal insulation slow cooling.Carbon Drill Bit