Approximate isothermal forging method of BT25 two-phase titanium alloy disk forge piece

Abstract

The invention discloses an approximate isothermal forging method of a BT25 two-phase titanium alloy disk forge piece. The process comprises the following steps of: heating a primary BT25 titanium alloy rod ingot to be below a phase transformation point by 30-75 DEG C and upsetting into a primary cake; heating the primary cake to be above the phase transformation point by 20-60 DEG C and drawing to return to the length of the primary rod ingot to obtain a secondary rod ingot; heating the secondary rod ingot to be below the phase transformation point by 30-75 DEG C, upsetting into a secondary cake and then punching into a ring blank; heating the ring blank to be above the phase transformation point by 20-60 DEG C, heating an upper forging die and a lower forging die to be below the phase transformation point by 10-20 DEG C, wherein the upper forging die and the lower forging die forge the ring blank by using the pressure of 30-60MN to ensure that the deformation of the ring blank in the forging dies reaches 30-50 percent by a strain rate of 0.001s<-1>-0.01s<-1> to form a disk forging piece by once heating, and heat treatment after forging adopts twice annealing treatment. The disk forging piece forged by using the method has better ideal network texture and high property, thus the method is suitable for manufacturing forging pieces such as compressor disks, turbine disks, and the like of aircraft engines.

Description

[0001] This application is a divisional application of the patent application with the application number 200810069069.4, the application date is December 25, 2008, and the invention title is "near-isothermal forging method for two-phase titanium alloy disc forging". technical field [0002] The invention relates to a forging method of a titanium alloy forging, in particular to a nearly isothermal forging method for a two-phase titanium alloy disc forging of BT25. Background technique [0003] Due to the harsh working environment and complex stress, the compressor discs and turbine discs of aero-engines are often forged with α+β two-phase titanium alloys with excellent comprehensive properties, such as TC17 and BT25. The disc forged with α+β type titanium alloy has a series of advantages such as high strength, good fracture toughness, high hardenability and wide forging temperature range, which can meet the needs of damage tolerance design and high structure and high reliabil...

AI Technical Summary

Problems solved by technology

[0004] In terms of the forging method of the two-phase titanium alloy, the Chinese invention patent specification CN1403622A published on March 19, 2003 discloses a titanium alloy quasi-beta forging process, which is used to perform quasi-beta forging on the α+β type two-phase titanium alloy At this time, the titanium alloy billet is heated to the region near the β transformation point temperature, that is, the range of 10°C below the transformation point temperature to 10°C above the transformation point temperature for forging. After cooling down from the furnace, the deformation of the forging is actually carried out in the α + β area. Although this method can obtain a highly plastic α phase network blue structure, the primary α phase of the network blue structure is still within 15%, and The patent specification only mentions in general that the clustered α phase of net blue weaving can be obtained, and does not give a specific metallographic diagram of the net blue structure. The net blue structure obtained by the α+β two-phase titanium alloy produced by this method not ideal organization