The basic processes of free forging include upsetting, elongation, punching, bending, twisting, displacement, cutting, and forging.
Free forging elongation
Elongation, also known as extension, is a forging process that reduces the cross-sectional area of the billet and increases its length. Elongation is commonly used for forging rod and shaft parts. There are two main methods of elongation: 1. elongation on a flat anvil. 2. Extend on the core rod. During forging, the core rod is inserted into the punched blank and then elongated as a solid blank. When drawing, it is generally not done in one go. The blank is first drawn into a hexagonal shape, forged to the required length, then chamfered and rounded, and the core rod is taken out. To facilitate the removal of the core rod, the working part of the core rod should have a slope of around 1:100. This elongation method can increase the length of the hollow billet, reduce the wall thickness, and maintain the inner diameter. It is commonly used for forging sleeve type long hollow forgings.
Free forging and upsetting
Upsetting is a forging process that reduces the height of the blank and increases the cross-sectional area. The upsetting process is mainly used for forging gear blanks and circular cake forgings. The upsetting process can effectively improve the microstructure of the billet and reduce the anisotropy of mechanical properties. The repeated process of upsetting and elongation can improve the morphology and distribution of carbides in high alloy tool steel. There are three main forms of upsetting: 1. Complete upsetting. Complete upsetting is the process of placing the blank vertically on the anvil surface, and under the impact of the upper anvil, the blank undergoes plastic deformation with a decrease in height and an increase in cross-sectional area. 2. End upsetting. After heating the blank, one end is placed in the leakage plate or tire mold to limit the plastic deformation of this part, and then the other end of the blank is hammered to form upsetting. The upsetting method of using missing plates is often used for small batch production; The method of upsetting the tire mold is often used for mass production. Under single piece production conditions, the parts that need to be upset can be locally heated, or the parts that do not need to be upset can be quenched in water after full heating, and then upset can be carried out. 3. Middle upsetting. This method is used for forging forgings with large mid-section and small end sections, such as gear blanks with bosses on both sides. Before upsetting the blank, both ends of the blank need to be pulled out first, and then the blank should be hammered vertically between the two leakage plates to upset the middle part of the blank. To prevent the bending of the billet during upsetting, the ratio of billet height h to diameter d h/d is ≤ 2.5.
Free forging punching
Punching is a forging process that involves punching through or through holes on a blank. There are two main methods of punching: 1. Double sided punching method. When using a punch to punch the blank to a depth of 2/3-3/4, remove the punch, flip the blank, and then align the punch with the position from the opposite side to punch out the hole. 2. Single sided punching method. The single side punching method can be used for billets with small thickness. When punching, the blank is placed on the backing ring, and the large end of a slightly tapered punch is aligned with the punching position. The blank is hammered in until the hole penetrates.
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Post time: Oct-25-2023
