Thermal expansion method for alpha-phase titanium alloy tapered ring rolled part

Abstract

The invention discloses a thermal expansion method for an alpha-phase titanium alloy tapered ring rolled part. The thermal expansion method comprises the following steps of: sleeving a hot-rolled tapered ring rolled part at the periphery of a pre-heated expanding block in an expanding machine, moving a pre-heated pressure block to match with the expanding bock, and pressing the pressure block on the upper end surface of the ring rolled part; starting the expanding machine, radically extruding the ring rolled part by the expanding block from the inner conical surface of the ring rolled part, and axially and synchronously extruding the ring rolled part by the pressure block to generate plastic deformation with expanded inner-outer diameter dimensions, wall thickness reduction and height reduction, thereby achieving a predetermined dimension, and completing expanding after retaining pressure; in an expanding process, keeping an expanding temperature at 700-850 DEG C, keeping expanding speed to be 0.52-1.52 mms / , keeping pressing speed to be 0.12-1.12 mm / s and keeping pressure retaining time for 42-82 seconds; rotating the ring rolled part by 30 degrees along the central axis; and reshaping after swelling a convex mark formed on the inner conical surface of the ring rolled part in the expanding process according to the operation. The dimension precision of the expanded ring rolledpart is + / -2 mm, and the thermal expansion method is mainly used for the fields such as aerospace.

Description

technical field [0001] The invention relates to a bulging method for a ring, in particular to a thermal bulging method for an α-phase titanium alloy conical ring rolling piece. Background technique [0002] The tapered ring rolling piece is a special-shaped ring rolling piece with a tapered longitudinal section, which is widely used in aviation, aerospace, gas turbines, special engineering equipment and other industries. Due to the difference in diameter between the upper and lower end surfaces of the tapered ring rolling piece, the difficulty of bulging is increased, and defects are prone to occur if the bulging process is not well controlled. [0003] The Chinese Invention Patent Specification CN102500706A published on June 20, 2012 discloses a method for thermal expansion of titanium alloy special-shaped ring rolling parts. Its inner ring surface is set on the periphery of the outer peripheral surface of the preheated bulging block, and the outer peripheral surface of th...

AI Technical Summary

Problems solved by technology

[0004] When the above method is used to bulge the α-phase titanium alloy tapered ring rolling piece, due to the difference in diameter between the upper and lower end surfaces of the tapered ring rolling piece, most of the strain during bulging is concentrated on the small end surface of the tapered ring rolling piece After the bulging is completed, a slope will appear on the large end surface of the tapered ring rolling piece from the inner diameter to the outer diameter, and a concave phenomenon will appear in the middle of the inner wall of the tapered ring rolling piece. If the bulging force is too large, it is easy to break the cone The rolling piece of the ring bulges upwards to form a bulging block

That is to say, after the bulging of the tapered ring rolling piece, there will be problems such as warping deformation, inner wall depression, and low dimensional accuracy.

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