Thermal bulging process for rectangular titanium-alloy rolled ring workpieces

Abstract

The invention discloses a thermal bulging process for rectangular titanium-alloy rolled ring workpieces, which includes steps of primary bulging; primary rotation; secondary rotation; secondary bulging and tertiary bulging. In the primary bulging, a rectangular titanium-alloy rolled ring workpiece which is treated by thermal rolling is sleeved on the periphery of a preheated bulging block in a bulging machine, and the bulging block squeezes the rolled ring workpiece axially along the inner circumference of the rolled ring workpiece after the bulging machine is started so that the primary bulging is completed, wherein the bulging temperature ranges from 780 DEG C to 830 DEG C, the bulging time ranges from 13s to 17s, the pressure holding time ranges from 10s to 12s, and the deflection ranges from 0.3% to 0.8%. The primary rotation is completed by rotating the rolled ring workpiece along the center axis by 45 degrees. The secondary bulging is completed by processes of the primary bulging, wherein the bulging temperature ranges from 750 DEG C to 800 DEG C, the bulging time ranges from 13s to 17s, the pressure holding time ranges from 10s to 12s, and the deflection ranges from 0.5% to 1%. The second rotation is completed by rotating the rolled ring workpiece again along the direction the same with that of the primary rotation. The tertiary bulging is completed by the processes of the primary bulging again, wherein the bulging temperature ranges from 700 DEG C to 770 DEG C, the bulging time ranges from 15s to 20s, the pressure holding time ranges from 12s to 14s, and the deflection ranges from 0.6% to 1%. The dimensional precision of the rolled ring workpiece can be 1%. to 2%. of the corresponding precision after the rolled ring workpiece is bulged, and the rolled ring workpiece is mainly used for the fields of space navigation 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 titanium alloy rectangular ring rolling piece. Background technique [0002] After the titanium alloy rectangular ring-rolled piece (referring to the ring-rolled piece with a rectangular cross-section in the longitudinal section) is rolled by the ring rolling mill, due to the influence of the rolling process and equipment limitations, its 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 stren...

AI Technical Summary

Problems solved by technology

Since this method relies on the flexible contact between the liquid and the inner peripheral surface of the ring to cold-expand the rectangular ring, it can only be suitable for some materials with small deformation resistance. Its main function is to strengthen the ring. Materials such as titanium alloys are not applicable; and 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 existing problems. The problem of low dimensional accuracy of ring rolling parts in the technology

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