Manufacturing method for improving tooth profile precision of spline shaft forging

Abstract

The invention relates to a manufacturing method for improving the tooth profile precision of a spline shaft forging. The method comprises the steps that a forging blank is placed into a heating furnace and heated to 850 DEG C-900 DEG C; primary pre-forging forming is performed, specifically, the work procedure includes that forward extrusion rod forming is performed on the blank which is heated to850 DEG C-900 DEG C; a pre-forged workpiece is placed into the heating furnace and cooled to 560 DEG C + / -10 DEG C with the cooling rate being 70-90 DEG C / h; secondary pre-forging forming is performed on the pre-forged workpiece, specifically, the work procedure includes that backward extrusion cup forming is performed on the forging which is cooled to 560 DEG C+ / -10 DEG C; the pre-forged workpiece is placed into the heating furnace with the temperature being 680 DEG C to be subjected to heat preservation for 1-1.5 h, and then taken out of the furnace to be subjected to normalizing and air cooling; shot blasting treatment and phosphorus saponification treatment are performed on the pre-forged workpiece; and cold extrusion forming is performed on the pre-forged workpiece, specifically, thework procedure includes that cold extrusion tooth profile forming is performed on the pre-forged workpiece which is subjected to phosphorus saponification treatment.

Description

technical field [0001] The invention relates to a manufacturing method for improving the tooth shape precision of spline shaft forgings, especially for the field of forging where multiple forging processes of pre-forging and final forging are required for warm extrusion or warm-cold extrusion combination. Background technique [0002] In the past, in the manufacturing process of die forging, we often only ensured the dimensional accuracy of the forging by improving the precision of the die, and did not pay special attention to controlling the dimensional accuracy of the forging during the forging preparation process. Due to the high temperature and large deformation of the pre-forging and final forging, the forging after the final forging will have thermal strain and stress concentration due to the coarse grain inside the forging and the large residual stress, which will have a great impact on the dimensional accuracy of the forging. Adverse effects, and prone to decarburiza...

AI Technical Summary

Problems solved by technology

Due to the high temperature and large deformation of the pre-forging and final forging, the forging after final forging will have thermal strain and stress concentration due to the coarse grains and large residual stress inside the forging, which will have a great impact on the dimensional accuracy of the forging. Adverse effects, and prone to decarburization and overburning, both affect product quality and reduce production efficiency

The traditional forging method is unreasonable and cannot effectively improve the dimensional accuracy of forgings

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