Blank for cold forging of forgings

The size and quality of the blank used for cold forging in the forging factory should be controlled accurately, and the end face should be flat and straight. For those with high requirements, the surface shall be peeled and can be turned or ground.
The purpose of softening and annealing heat treatment is to reduce the strength of raw materials, ensure uniform performance and improve plasticity. General annealing treatment shall be adopted for low carbon steel, and spheroidizing annealing treatment shall be adopted for medium carbon steel and low alloy steel.
The lubrication of cold forging is very important. It can reduce the load of cold forging, improve the die life and the quality of cold forging. Generally, the lubrication treatment is to form a firm film on the surface of the blank to reduce the friction resistance and cold forging force during the cold forging process. Before lubricating treatment, the blank surface shall be cleaned, including alkali washing, oil removal, acid cleaning or shot blasting, scale cleaning and water cleaning, to keep the blank surface clean.
The shape of the pre-forging step directly affects the forming of the final forging step. The general principle of design is that in order to ensure that the final forging die chamber is filled, the designed pre-forging blank should be upset in the final forging die chamber as far as possible, that is, the height of the pre-forging step should be 6-8 mm larger than the final forging step, and the diameter should be 0.52 mm smaller than the final forging step. For different types of forgings, there are different design features.
Rod forgings with a large part. Punched forgings.
Punching times and punching depth distribution. The number of punching depends on the ratio of punching depth to punching diameter. When the punching depth is distributed for many times, the first punching depth is shallow, because the first punching blank is not stable, and the other punching depths are basically equal.