Forging method of driving shaft for gearbox

Abstract

The invention discloses a forging method of a driving shaft for a gearbox. The forging method of the driving shaft for the gearbox comprises the following steps: a step a of pouring a cylindrical blank material, wherein the cylindrical blank material comprises chemical components, by weight percent: no smaller than 0.096% but no greater than 0.150% of C, no smaller than 2.1% but no greater than 2.40% of Si, no smaller than 1.1% but no greater than 1.30% of Mn, no smaller than trace amountbut no greater than 0.033% of P, no smaller than trace amount but no greater than 0.0260% of S, 0.11-0.22% of Ni, no smaller than 8.50% but no greater than 11.50% of Cr, no smaller than trace amount but no greater than 0.018% of B, and the balance of Fe and inevitable included impurities; and the step a comprises the following steps: decreasing the temperature of blank bodies shaped in a pouring way to 350 DEG C, then heating the blank bodies to 670 to 760 DEG C for 3-5h heat preservation, cooling the blank bodies in a furnace to 300 DEG C for 4h heat preservation, reheating the blank bodies to 650 to 760 DEG C for 17h heat preservation, cooling the blank bodies to 400 DEG C at a speed of 50 DEG C per hour and finally cooling the blank bodies to 140 DEG C at a speed of 20 DEG C per hour; and a step b of forging, wherein the step b comprises the following steps: a step 1 of selectively using 30-diameter round steel and cutting by using a shearing machine, wherein the length of a sheared rough blank piece is 70.3mm; and a step 2 of putting the rough blank piece of the step 1 in an intermediate frequency heating furnace for heating at a heating temperature of 1120 to 1180 DEG C and keeping the heating for 3.6min. The forging method of the driving shaft for the gearbox is beneficial to the large-batch industrial production of the driving shaft for the gearbox; and moreover, the phenomena of dirt inclusion and impossible fullness occurring during the forging process are reduced, the mechanical performance of a product is further improved, the product material is saved and the service life of a die for the product is prolonged.

Description

technical field [0001] The invention relates to a forging method of a drive shaft for a gearbox. Background technique [0002] The driving shaft is a key part of the car. Due to its particular shape and the importance of its performance, it is difficult to forge it. The distribution of materials and the selection of processes need to be carefully considered. For this reason, the development of reasonable forging methods for such forgings has also attracted attention both at home and abroad. [0003] At present, the conventional technological process of domestic drive shafts is: heating, pre-forging, final forging, and finishing. The disadvantages of this solution are: a large-tonnage press is required, high energy consumption, low material utilization rate, resulting in high forging cost. The forgings produced by the technical process of this scheme are prone to contamination, dissatisfaction, etc., the defect rate is 5%, and the utilization rate of raw materials is only 2...

AI Technical Summary

Problems solved by technology

The disadvantages of this solution are: large-tonnage presses are required, high energy consumption, low material utilization rate, resulting in high forging costs

The forgings produced by the technical process of this scheme are prone to contamination, dissatisfaction, etc., the defect rate is 5%, and the utilization rate of raw materials is only 20-30%. Due to reasons such as excessive flash, the life of the mold is only About 5000-6000 pieces