Advantages and disadvantages of shaft forgings and profiles and their application range

Relatively speaking, in the case of normal forging ratio and processing technology, the shaft forgings after forging are generally more uniform in chemical composition, fine in structure and high in grain size than the profiles, so the strength and toughness are better under the same processing conditions.

For example, shape structure and general profile will be more serious than hammer forging, which will greatly affect various performance, radial and tangential performance indexes. The workpiece with required radial or tangential performance will not meet the requirements.

In addition, hammering forgings can increase the impact resistance, that is, the impact energy Ak value, and when the number of hammering per minute reaches the value, the transverse and longitudinal Ak values are close. The main reason for the high performance of hammer forging is that in the process of hammering, most (or part) of the defective tissue and large tissue in the matrix will be broken and recombined, so that the overall material composition is uniform, the structure and grain are fine, and the strength and toughness index are increased at the same time. Obviously, this is mainly to say that the hammer forging and hot rolling profile performance comparison, if it is hydraulic or hydrostatic forming forging, its performance should be in between the two.

The shaft part is one of the typical parts in the machine. It is mainly used in machinery supporting gear, belt wheel, CAM and connecting rod and other transmission parts to transfer torque. According to different structural forms, the shaft can be divided into a ladder shaft, taper spindle, optical shaft, hollow shaft, crankshaft, camshaft, eccentric shaft, a lot of screw, etc.. It is mainly used to support the transmission components, transmission torque and load. Shaft parts are rotary parts, the length is greater than the diameter, generally by concentric shaft cylindrical surface, conical surface, internal hole and thread and the corresponding end surface composition. According to the different shape of the structure, shaft components can be divided into optical shaft, ladder shaft, hollow shaft and crankshaft.

The axis with the length-diameter ratio less than 5 is called the short axis, and the axis greater than 20 is called the slender axis. Most number axes are between the two.

Round bars and forgings are commonly used in shaft blanks. Large shafts or shafts with complex structure are castings. After the blank is heated and forged, the fiber structure inside the metal can be evenly distributed along the surface to obtain higher tensile, bending and torsional strength.

According to the different production scale, there are two ways of blank forging: free forging and die forging. Free forging is mostly used for small and medium batch production, while die forging is used for mass production.