Method for manufacturing annular molded article

Abstract

The present invention is a method for manufacturing an annular molded article provided with a forging step for fabricating a disk-shaped forged article by forging an alloy material, and a ring-rolling step for fabricating an annular molded article by ring-rolling an annular intermediate article obtained by forming a through-hole in the forged article, wherein said method is characterized in that hot forging is performed at least twice in the forging step. In the hot forging, the strain rate is 0.5 s<-1> or less, the absolute value [epsilon][theta]1 of circumferential-direction strain in the forged article is 0.3 or greater, the absolute value [epsilon]h of height-direction strain of the forged article is 0.3 or greater, and the ratio between these absolute values for strain ([epsilon]h / [epsilon][theta]1) is 0.4 to 2.5 inclusive.

Description

technical field [0001] The present invention relates to a method for producing an annular formed body used, for example, as a processing stock for producing annular products such as turbine disks for aircraft engines. [0002] This application claims priority from Japanese Patent Application No. 2013-069205 filed on March 28, 2013, the entire contents of which are hereby incorporated by reference. Background technique [0003] The turbine disk is an annular member having a through hole, and is configured to rotate together with a plurality of turbine blades arranged on the outer peripheral side of the turbine disk. [0004] The outer peripheral portion of the turbine disk is exposed to combustion gas and reaches a high temperature of about 600°C to 700°C, while the inner peripheral portion is maintained at a relatively low temperature, so heat is repeatedly generated inside the turbine disk as the engine is started and stopped. stress. Therefore, it is desirable for turbin...

AI Technical Summary

Problems solved by technology

However, in general, anisotropy in mechanical properties (strength properties) is more likely to occur in ring-rolled products than in forged products, and thus ring rolling is not suitable for manufacturing required mechanical properties such as turbine disks and the like. isotropic product of

[0009] A method of forming a ring-shaped formed body by a combination of forging and ring rolling may be used; however, if this method is used, a problem may arise such that final forging must be performed after ring rolling to obtain a desired uniform and fine structure , the manufacturing process may thus become complicated and the manufacturing cost may become higher

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