Method of manufacturing annular molding

Patent metadata

Field	Value
Publication number	US-9592547-B2
Application number	US-201213709388-A
Country	US
Kind code	B2
Filing date	Dec 10, 2012
Priority date	Dec 10, 2012
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A method of manufacturing an annular material includes: a forging process of making a discoid forged material by forging an alloy material; and a ring rolling process of making an annular material by performing ring rolling on an annular intermediate made by forming a through-hole in the forged material. In the forging process, hot forging which achieves an absolute value εθ 1 of a strain in a circumferential direction of the forged material that is greater than or equal to 0.3, an absolute value εh of a strain in a height direction of the forged material that is greater than or equal to 0.3, and a ratio εh/εθ 1 between the absolute values of the strains that is in a range of 0.4 to 2.5 is performed at least two or more times.

First claim

What is claimed is:

1. A method of manufacturing an annular material comprising:
a forging process of making a discoid forged material by forging an alloy material; and
a ring rolling process of making an annular material by performing ring rolling on an annular intermediate made by forming a through-hole in the forged material,
wherein, in the forging process, hot forging is performed at least twice in such a way that an absolute value εθ 1 of a strain in a circumferential direction of the forged material that is greater than or equal to 0.3, an absolute value εh of a strain in a height direction of the forged material that is greater than or equal to 0.3, and a ratio εh/εθ 1 between the absolute values of the strains that is in a range of 0.4 to 2.5;
the method further comprising an annular intermediate material preparing process by boring the discoid forged material to form a through-hole therein in such a way that a ratio T/H of a thickness T of the annular intermediate material in a radial direction orthogonal to the axial line direction to the height H is set in a range of 0.6 to 2.3, wherein
the annular material is for a turbine disk of an aircraft engine,
the discoid formed material obtained in the forming process has a height H along an axial line direction of the discoid forged material of 60 mm to 500 mm, and
εh is obtained by a formula (1):



ɛ
⁢

⁢
h



=



ln
⁡

(

h
1

h
0

)



,

(
1
)

h 0 and h 1 being lengths in a height direction before and after forging, respectively, and
εθ 1 is obtained by a formula (2):



ɛ
⁢

⁢
θ



=



ln
⁡

(

θ
1

θ
0

)



,

(
2
)

θ 0 and θ 1 being average radiuses before and after forging, respectively.

2. The method of manufacturing an annular material according to claim 1 ,
wherein, in the ring rolling process, hot rolling in which 0.5 or higher of an absolute value εθ 2 of the strain in the circumferential direction in the annular material is exerted is performed, and
a grain size of a product region in the annular material is greater than or equal to 8 in terms of ASTM grain size number.

3. The method of manufacturing an annular material according to claim 2 ,
wherein a grain size difference in the product region of the annular material in a cross-section including an axial line of the annular material is in a range of ±2 as an ASTM grain size number difference.

4. The method of manufacturing an annular material according to claim 1 ,
wherein, in the forging process, a grain size of the forged material is caused to be greater than or equal to 7 in terms of ASTM grain size number.

5. The method of manufacturing an annular material according to claim 1 ,
wherein the annular intermediate is made so that a ratio T/H of a thickness T in a radial direction in the annular intermediate and a height H along an axial direction of the annular intermediate is in a range of 0.6 to 2.3 and is thereafter subjected to ring rolling to cause a grain size difference between a plurality of equivalent positions equally set in the circumferential direction in the annular material to be in a range of ±1.5 as an ASTM grain size number difference.

6. The method of manufacturing an annular material according to claim 1 ,
wherein a temperature of the ring rolling process is in a range of 900 to 1050° C.

7. The method of manufacturing an annular material according to claim 1 ,
wherein a temperature of the forging process is in a range of 950 to 1075° C.

8. The method of manufacturing an annular material according to claim 1 ,
wherein, in the forging process, the absolute value εθ 1 is set to be in a range of 0.3 to 1.3, and the absolute value εh is set to be in a range of 0.3 to 1.3.

9. The method of manufacturing an annular material according to claim 1 ,
wherein, in the ring rolling process, the absolute value εθ 2 is set to be in a range of 0.5 to 1.3.

Assignees

• Mitsubishi Materials Corp

Inventors

• Takizawa Hideo
• Ishiwari Yuji
• Kikuchi Hiroaki
• Ohsone Jun

Classifications

• B21J5/02

  Die forging; Trimming by making use of special dies {; Punching during forging} · CPC title

• B21J1/025

  affecting grain orientation · CPC title

• B23P15/006

  turbine wheels · CPC title

• B21K1/28

  wheels; discs · CPC title

• B21J1/04

  Shaping in the rough solely by forging or pressing · CPC title