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(1), in order to ensure the machining accuracy, rough, finishing the best separately. Because roughing, cutting a large amount of cutting force by the workpiece, clamping force, heat and more, and the processing of the surface there is more significant work hardening phenomenon, the workpiece there is a large internal stress, if the rough, roughing Continuously, the precision of the finished part is quickly lost due to the stress redistribution. For some high precision machining parts. After roughing and finishing, cryogenic annealing or aging treatments should also be arranged to eliminate the internal stresses.

(2), reasonable selection of equipment. Rough cutting is to cut off most of the machining allowance, does not require a higher machining accuracy, so the roughing should be larger, less accurate machine tool, finishing process requires a higher precision Machine tool processing. Coarse, finishing in different machine tools were processed, both to give full play to equipment capabilities, but also extend the life of precision machine tools.

(3), in the mechanical processing route, often arranged with heat treatment processes. Heat treatment process positions are as follows: In order to improve the metal cutting performance, such as annealing, normalizing, quenching and tempering, generally arranged before machining. In order to eliminate internal stress, such as aging, quenching and processing, generally arranged after roughing, finishing before. In order to improve the mechanical properties of parts, such as carburizing, quenching, tempering, etc., generally arranged after machining. If the heat treatment after a larger deformation, the final processing must be arranged.