To ensure precision machining accuracy. Many workpieces are subjected to cutting forces, clamping forces, and more thermal values, should be separately roughing and finishing. Because when rough machining. Very easy to lead to surface hard bottoming, the workpiece internal has a large internal stress, if finishing and roughing is continuous after finishing fine parts precision will be accompanied by ground stress again all over, quickly will be lost. For some parts with high machining accuracy. After rough machining and before finishing should be ultra-low temperature quenching or aging treatment to remove internal stresses.
The main process of rough machining is to disconnect most of the machining margin, and rough machining CNC lathe only needs high power and low precision production machining. Finishing requires a finer CNC lathe. Not the same CNC lathe on the rough and finish machining, do not provide for higher processing accuracy. Thus. Not only can fully use the characteristics of the machine and equipment, and can increase the use of precision machinery period.
Heat treatment is often required in the machining process. The heat treatment process is assigned as follows: To improve the cutting performance of the metal. Generally performed before machining. To remove internal stresses, such as quenching, hardening, and heat treatment. Such as aging treatment and tempering treatment are generally carried out after rough machining and before finishing machining. In order to improve the physical properties of the parts, nitriding, heat treatment, quenching, etc., generally after machining. If there is deformation after heat treatment, it is important to assign the final production process.