Manufacturing method for material for ring rolling

Patent metadata

Field	Value
Publication number	US-9719369-B2
Application number	US-201414778021-A
Country	US
Kind code	B2
Filing date	Mar 18, 2014
Priority date	Mar 21, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A manufacturing method provides a high-quality material for ring rolling. The manufacturing method of the material for ring rolling includes a step of heating a disk-shaped material for hot forging to a hot working temperature, a step of arranging the material for hot forging onto a lower die having a convex portion with a truncated conical shape, a step of forming a thin portion by pressing a center portion of the material for hot forging by using an upper die having a convex portion with a truncated conical shape, and a step of manufacturing a material for ring rolling by removing the thin portion wherein a center of gravity on a half section of the material for ring rolling is located so as to be closer to an outer peripheral surface of the half section than a center of the half section in a thickness direction of the half section.

First claim

The invention claimed is:

1. A manufacturing method for a material for ring rolling, to be shaped by rolling, to manufacture a ring product to be used in high temperature environments, the manufacturing method comprising:
heating a disk-shaped material for hot forging to a hot working temperature;
forming a portion having a reduced thickness in the disk-shaped material by pressing a center portion of the disk-shaped material with an upper die having a convex portion with a truncated conical shape and a lower die having a convex portion with a truncated conical shape; and
manufacturing the material for ring rolling by removing the portion having the reduced thickness, wherein a shape of a half section of the material for ring rolling includes a shape forming: a height reducing portion having a height from a center line which divides the half section into halves in a height direction of the half section, gradually reduced toward an inner peripheral surface of the material for ring rolling, and a linear portion including end surfaces which are respectively positioned upward and downward and respectively have constant heights, and wherein the height reducing portion and the end surfaces of the linear portion are shaped during the forming of the portion having the reduced thickness by the pressing with the upper die and the lower die;
wherein a center of gravity on the half section of the material for ring rolling is located so as to be closer to an outer peripheral surface of the material for ring rolling than a center of the half section in a thickness direction of the half section,
wherein the material for ring rolling is formed such that a shape of the half section includes the height reducing portion having the height from the center line which divides the half section into halves in the height direction is gradually reduced toward the inner peripheral surface and the shape of the half section is formed in a substantially linear symmetry so as to define the center line as a symmetrical axis of the half section, and
wherein a height of the inner peripheral surface is from 20% to 50% of a maximum height of the material for ring rolling.

Assignees

• Hitachi Metals Ltd

Inventors

• Yagami Tetsuya
• Teramae Toshiya
• Fujita Etsuo
• Nagao Shinya
• Mukouse Remi
• Iwasa Naoyuki
• Fukui Tsuyoshi
• Aoki Chuya

Classifications

• B21J1/025

  affecting grain orientation · CPC title

• B21J5/02

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

• B21B45/004

  Heating the product · CPC title

• B21H1/06 Primary

  rings of restricted axial length (extending closed shapes of metal bands by simultaneous rolling at two or more zones B21B5/00) · CPC title

• B21K1/761

  rings · CPC title