Hot bulging method for rectangular bearing steel rolled ring

Abstract

The invention discloses a hot bulging method for a rectangular bearing steel rolled ring; the hot bulging method comprises the following steps of: sleeving a rectangular bearing steel hot-rolled ring at the periphery of a preheated bulging block in a bulging machine, starting the bulging machine so that the bulging block extrudes the rolled ring along the radial direction on the surface of the inner circumference of the rolled ring to complete primary bulging, wherein the bulging temperature is 860 DEG C to 900 DEG C, the bulging time is 20s-30s, the pressure holding time is 12s-15s, and the deformation amount is 0.4%-0.7%; then leading the rolled ring to rotate by 45 degrees along a central axis to complete primary rotation; afterwards, carrying out secondary bulging according to the operation, wherein the bulging temperature is 830 DEG C to 870 DEG C, the bulging time is 25s-35s, the pressure holding time is 18s-22s, and the deformation amount is 0.6%-1%; rotating the rolled ring again to complete secondary rotation according to the primary rotation direction; and carrying out third bulging according to the operation, wherein the bulging temperature is 800 DEG C to 840 DEG C, the bulging time is 25-40s, the pressure holding time is 16s-20s, and the deformation amount is 0.6%-1.1%. The dimensional accuracy of the bulged rolled ring can reach 0.1%-0.2% of the corresponding dimension; and the bulged rolled ring is mainly applied to the fields of aerospace and the like.

Description

technical field [0001] The invention relates to a bulging method for a ring, in particular to a thermal bulging method for a bearing steel rectangular ring rolling piece. Background technique [0002] Bearing steel rectangular ring-rolled pieces (referring to the ring-rolled piece with a rectangular cross-section in the longitudinal section) are rolled by the ring rolling mill. Due to the influence of the rolling process and equipment limitations, the dimensional accuracy is generally not high; only in the shape of the ring-rolled piece In the case of ideal and excellent equipment performance, the dimensional accuracy can reach 3‰~5‰ (three thousandths to five thousandths) of the corresponding size. If the control is not good in the follow-up processing process, defects such as warping, deformation and even cracking may easily occur. [0003] The Chinese invention patent specification CN 101367104A published on February 18, 2009 discloses a hydraulic bulging strengthening p...

AI Technical Summary

Problems solved by technology

This method does not disclose in detail how to improve the dimensional accuracy of the ring through bulging, but it is generally concluded that the purpose of improving the forming accuracy of the retaining ring can be achieved, that is, this method cannot solve the dimensional accuracy of the ring rolled piece existing in the prior art low problem

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