Thermal expansion method for titanium alloy flash welding collar piece

Abstract

The invention discloses a thermal expansion method for a titanium alloy flash welding collar piece, which comprises the following steps: heating an annealed titanium alloy flash welding collar piece, sleeving the titanium alloy flash welding collar piece on the periphery of a preheated expanding block in an expanding machine, and starting the expanding machine to allow the expanding block to press the collar piece radically from the internal circumferential surface of the collar piece to accomplish primary expansion, wherein the expansion temperature is 750 to 850 DEG C, the expansion time is 10 to 15 seconds, the pressure-keeping time is 8 to 9 seconds and the deformation rate is 0.1 to 0.15 percent; rotating the collar piece 45 DEG around a central axis to accomplish primary rotation; performing secondary expansion by the same operation, wherein the expansion temperature is 730 to 830 DEG C, the expansion time is 22 to 23 seconds, the pressure-keeping time is 18 to 20 seconds, and the deformation rate is 0.7 to 0.9 percent; rotating the collar piece in the same direction as the primary rotation to accomplish secondary rotation; and performing tertiary rotation by the same operation, wherein the expansion time is 700 to 800 DEG C, the expansion time is 33 to 43 seconds, the pressure-keeping time is 28 to 30 seconds and the deformation rate is 0.8 to 1 percent. The specification precision of the expanded collar piece can reach 0.1 to 0.2 of a corresponding specification, and the expanded collar piece is mainly used in the field of space navigation.

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 flash welding ring. Background technique [0002] After the titanium alloy flash welding ring is welded and formed, due to the influence of the welding process, the welded ring has a straight edge on its circumference, and the high stress of the ring after welding will cause the ring to warp and deform, resulting in It is in the shape of an irregular ring, and its dimensional accuracy is poor. In general, the welded ring can only be used after reaching the required size through a full circle. [0003] The Chinese invention patent specification CN 101367104A published on February 18, 2009 discloses a hydraulic bulging strengthening process for replenishing fluid outside the retaining ring of a turbogenerator. Then inject the closed space formed by the fixed upper cone mold, the moving lower cone mold and the retaining ring through the pa...

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 ring, it is only suitable for some materials with small deformation resistance, and its main function is to strengthen the ring. For materials with greater deformation resistance, 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 problems in the prior art. There are problems with poor roundness and dimensional accuracy of flash welded rings

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