Hitachi Metals, Ltd.

Proterial, Ltd.

Naoyuki Iwasa

Tsuyoshi Fukui

Etsuo Fujita

Chuya Aoki

Shinya Nagao

Remi Mukouse

Tetsuya Yagami

Toshiya Teramae

Daigo Ohtoyo

Taku Hirosawa

The present invention provides a method for producing a ring-rolled material of an Fe&#x2014;Ni based superalloy which inhibits AGG, has a fine-grained structure having an ASTM grain size number of at least 8, and has high circularity. A method for producing a ring-rolled material of an Fe&#x2014;Ni based superalloy having a composition of an Alloy 718 comprises: heating a ring-shaped material for ring rolling having the composition, in a temperature range of 900&#xb0; C. to 980&#xb0; C., and performing finishing ring rolling, as a finishing ring rolling step; heating the ring-rolled material that has been subjected to the finishing ring rolling, in a temperature range of 980 to 1010&#xb0; C.; and correcting ellipticalness while expanding a diameter of the ring-rolled material by using a ring expander.

Production method for ring-rolled material of Fe&#x2014;Ni-based superalloy

A ring rolling mill includes: a rotary drive main roll and a mandrel roll, which are for reducing the thickness of and rolling a ring-shaped material from the radial direction; a pair of rotary drive axial rolls for reducing the thickness of and rolling the ring-shaped material from the axial direction; a measuring roll for measuring the diameter of the ring-shaped material during rolling; and a speed control unit for controlling the speed of the axial rolls. The speed control unit is configured to repeat measuring the diameter at predetermined time intervals &#x394;t and comparing a measurement value Lof the diameter at time t and a measurement value Lof the diameter at time t+&#x394;t, and the speed control unit is further configured to maintain the speed of the axial rolls unchanged upon the result of the comparison being L&#x3c;L.

Ring rolling mill and method for manufacturing ring rolled material

The present invention provides a high quality material for ring rolling. The material includes radially outer and inner peripheral surfaces. In the material, a center of gravity on a half section is located so as to be closer to the outer peripheral surface in contact with a main roll than a center of the half section in a thickness direction, a shape of the half section includes a height reducing portion having a height from a center line dividing the half section into halves in a height direction, this height is gradually reduced toward the inner peripheral surface in contact with a mandrel roll, and the shape is formed in a substantially linear symmetry such that the center line is a symmetric axis. A height of the inner peripheral surface is from 20% to 50% of a maximum height of the material.

Material for ring rolling

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.

Manufacturing method for material for ring rolling

Growing community of inventors

Yasugi, Japan

Naoyuki Iwasa