Method for preventing circularity over tolerance of large gear ring after heat treatment

Abstract

The invention discloses a method for preventing roundness deviation of a large gear ring after heat treatment. The method comprises the following steps: jacking the ellipsoidal deformed gear ring generated after heat treatment quenching at 1 / 4 height of the large gear ring at a direction of the minor axis of the large gear ring by a lifting jack until the ellipsoidal deformed gear ring is jacked to the required size; jacking a jacking shaft previously prepared at the 3 / 4 height of the large gear ring near the direction of the minor axis jacked by the lifting jack; removing the lifting jack; carrying out a normal tempering treatment on the large gear ring with the jacking shaft in a furnace; and cooling down the gear ring after tempering to room temperature, removing the jacking shaft to end the deformation correction. In the invention, only the steps for measuring deformation and installing the jacking shaft are added in the original heat treatment process flow, and the success rate for correction can be up to 100%. The two steps both have no influence on the original heat treatment process; therefore, the invention realizes the purposes of no extra addition of working procedure, working period, energy consumption and labor intensity, thereby avoiding the occurrence of waste products and lowering the manufacturing cost of products.

Description

technical field [0001] The invention relates to a metal material heat treatment technology, in particular to a method for preventing the roundness of a large ring gear from being out of tolerance after heat treatment. Background technique [0002] Quenching and tempering treatment in the parts heat treatment process usually refers to heating the steel parts to a temperature above the austenitization temperature Ac3 or Ac1 point, keeping it for a certain period of time, and then cooling at the critical cooling rate to obtain a martensite structure, Then carry out the heat treatment process of high temperature tempering. Due to the inhomogeneity of the temperature and structural changes of the parts interface during heating and cooling, as well as the gravity and clamping force of the parts, under the action of internal stress and external force, the parts will be more or less distorted after heat treatment. There are often two types of deformation in ring quenching and tempe...

AI Technical Summary

Problems solved by technology

However, due to the influence of too many factors in heat treatment, especially the existence of some accidental factors, there will still be a small number of parts whose deformation exceeds the machining allowance; and this type of large ring gear has complicated processing procedures, and if it is scrapped, it will cause huge economic losses , so it is necessary to correct

[0004] In the literature search of the existing technical documents, it is found that most of the heat treatment correction processes of this type of large ring gear currently use the flame hot spot method and the tooling setting method to correct the elliptical deformation of the large ring gear, but these two methods require additional processes, The construction period, energy consumption and labor intensity are not only too complicated but also long cycle and high cost for batch heat treatment parts

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