The forging process is changed to the process of turning holes, saving materials, simple process and low equipment tonnage.
The original process uses a round bar 40cr to cut into a small cylinder, then forges it into a blank, rough turning, quenching and tempering heat treatment to 22-30hrc, finishing turning, punching 5 holes and trimming, and then drilling 5 holes with double-sided chamfering , and finally grind the plane.
Our initial process uses round rods to be formed by rough turning. The thickness of the flanges varies from 2.6 to 2.7 to 2.8. Measure the size and make a record and take it for quenching and tempering heat treatment to see the amount of deformation. Then choose the thickness of the plate. Flip hole processing. Then it was tempered to 28hrc and brought back for measurement, and it was found that the deformation was 0.02mm. When I finally chose the board, I found that only 3.0 is better to purchase. Next, we used the flanging-hole process, and the part was broken. It had to be changed to a deep drawing process, but the deep drawing is very difficult, the elongation is only 15, and it is difficult to eliminate and flatten the wavy lines after deep drawing. At that time, there will be only 0.5mm allowance on both sides, which is difficult to process, and the r angle is very large, at least 5mm, which will cause the r angle to not be able to be machined. I had to use a high-frequency coil to burn it down, and then take it without complete annealing and then do the flanging-hole process, because the bottom surface is flat after the hole is turned, but a new problem has arisen, the height of the hole is enough, but the inner and outer diameters are different anyway. The car is not available, and the thinner material is already out of material. To sum up, it is feasible to use the hole-turning process for the product, and annealing is also feasible. Only thicker raw materials, we directly use 4.0mm 40cr, still have a 10% defective rate. Finally, the 5.0mm 40cr was used to turn the hole, which perfectly solved all the problems.
Process flow: buy width:110mm plate 40cr, punch it into a 105mm diameter disc, punch the middle hole into 12mm, then burn red with high frequency, directly punch and turn the hole, take it out for external heat treatment and tempering, take it back for fine car processing, Leave a margin of 0.1mm for the flange surface for the grinding machine. After finishing the turning, punch the hole and cut the edge, and then grind the machine to make a flatness of 0.03mm, and then pack it for shipment.