Machining of mechanical forgings is the process of changing the external dimensions or functions of forgings with various machines. With the rapid development of modern machining and the rapid development of machining skills, a large number of machining skills have gradually emerged. Nowadays, large-scale machining has put forward higher requirements on production skills, not only to achieve high accuracy of foot shape and position, but also to achieve high quality of appearance. The following shares with you the purpose and requirements of heating during the processing of large mechanical forgings.

A, the purpose and requirements of forging heating

1, the purpose of heating: to improve the plasticity of the metal, reduce the deformation resistance of the metal, so that it is easy to shape, forging to obtain good microstructure and mechanical properties.

2、Heating requirements.

(1) in the metal material allowed temperature conduction and internal stress conditions, rapid heating to a predetermined temperature, improve production and save energy.

(2) minimize the absorption of oxygen, hydrogen, nitrogen and other harmful gases, reduce oxidation, decarburization or hydrogen embrittlement and other defects, and improve the heating quality of forgings.

(3) In the low-temperature heating stage, prevent the improper heating from causing excessive temperature difference between the outer layer and the core of the metal profile, resulting in excessive thermal stress and other internal stresses superimposed, causing the material to fracture.

(4) Accurately implement the prescribed heating specifications, such as heating temperature, speed, time, holding and other heating conditions, to prevent overheating, overburning and other defects.

Second, a part of the blank around its axis relative to another part of the forging process is called twisting, commonly used in forging crankshafts, connecting rods, twist drills and other forgings of different planes. Operation points are as follows.

1, in order to prevent defects caused by severe metal deformation during the twisting process, the surface of the twisted part is smooth and free of defects. For thick and short journals, twist after rough turning.

2、The twisted part is heated to the plastic temperature range and heated evenly along its length.

3, after the billet is twisted, it should be cooled slowly, and the forgings with strict requirements should be annealed.