Drawing, also known as drawing, is a forging process, which can reduce the cross-sectional area of the blank and increase the length of the blank. Stretching is often used to forge rod and shaft parts. There are two main ways to draw the length: 1. Stretch the length on a flat anvil. 2. When drawing and forging a mandrel, firstly insert the mandrel into a blank with a punch hole, and then draw it into a solid blank. When drawing the length, it is generally not a one-time drawing. Firstly, the blank is drawn into a hexagon, forged to the required length, then chamfered and rounded, and the mandrel is taken out. In order to take out the spindle, the working part of the spindle should have an inclination of about 1: 100. This drawing method can increase the length of hollow blank, reduce the wall thickness and keep the inner diameter unchanged. Commonly used for forging sleeve-like long hollow forgings. Upsetting is a forging process that reduces the height of blank and increases the cross-sectional area. Upsetting technology is mainly used for forging gear blanks and disc forgings. Upsetting process can effectively improve the microstructure of billet and reduce the anisotropy of mechanical properties. Repeated upsetting and drawing can improve the morphology and distribution of carbides in high alloy tool steel. Upsetting mainly has the following three forms: 1. Totally upset. Complete upsetting is to put the blank vertically on the anvil surface. Under the action of the upper anvil hammer, the blank will produce plastic deformation, the height will decrease and the cross-sectional area will increase. 2. After the blank is heated, put one end into the bushing or tire mold to limit the plastic deformation of this part, and then upset the other end of the blank with a hammer. Leakage upsetting method is mostly used in small batch production; The upsetting method of tire mold is mostly used in mass production. In the case of single-piece production, the part that needs upsetting can be heated locally, and the part that doesn't need upsetting can also be completely heated, chilled in water, and then upset. 3. Intermediate disturbance This method is used to forge forgings with large middle section and small cross sections at both ends, such as gear blanks with bosses on both sides. Before upsetting the blank, both ends of the blank must be sharpened first, and then the blank should be erected between two leaking hammer discs to upset the middle part of the blank. In order to prevent the blank from bending during upsetting, the ratio of the height h to the diameter d of the blank, h/d, is ≤ 2.5. Punching [punching] is a forging process of punching through holes or watertight holes in the blank. There are two main punching methods: 1. Double-sided punching method. When punching the blank to a depth of 2/3~3/4 with the punch, take out the punch, rotate the blank, and then align the position of the punch from behind to punch out the hole. 2. Single-sided punching method The blank with small thickness can be punched on one side. When punching, put the blank on the backing ring, align the big end of the slightly tapered punch with the punching position, and knock the blank in with a hammer until the hole penetrates. Bending [Bending] The forging process of bending a blank into a specified shape with a certain mold is called bending. There are two common bending modes: 1. Forging hammer bending method. One end of the blank is pressed by the upper anvil and the lower anvil, and the other end is struck by a sledgehammer or pulled by a crane to bend it. 2. The die bending method can obtain small forgings with accurate shape and size by bending in the buffer die. Cutting [cutting] refers to the forging process of cutting a blank into several parts or parts, or cutting a part from the outside of the blank or cutting a part from the inside. Dislocation [Dislocation] refers to a forging process in which one part of a blank is parallel to another part for a certain distance, but the axis is still parallel, and is often used for forging crankshaft parts. When shifting, the blank is cut locally first, and then the impact force or pressure with the same size and opposite method and perpendicular to the axis is applied on both sides of the incision to shift the blank. Forging joint [forging joint] is a forging process in which the blank is heated to a high temperature in a furnace and then struck quickly with a hammer to combine the two into a solid state. Forging methods include lap joint, butt joint and bite joint. The strength of forged joint can reach 70%~80% of the strength of the connected material. Torsion is a forging process in which one part of wool rotates at a certain angle relative to another part around its axis. This process is mainly used for forging multi-throw crankshaft and correcting some forgings. When the torsion angle of small blank is not large, hammering method can be used. The cracks reported by the defect editor may be caused by poor blank quality, insufficient heating, too low forging temperature, improper cooling of forgings and incorrect forging method. The end sag and axial crack may be due to the lack of heat inside the blank or the incomplete forging of the whole section of the blank, and the deformation only occurs on the surface of the blank. Folding may be caused by the fact that the feed of blank is less than the reduction of one side during forging.