Hitachi Metals, Ltd.

Tsuyoshi Fukui

Naoyuki Iwasa

Koji Sato

Hideki Matsumoto

Etsuo Fujita

Chuya Aoki

Toshiya Teramae

Remi Mukouse

Katsunori Iwasaki

Toshiaki Nonomura

Shinya Nagao

Tetsuya Yagami

Eiji Shimohira

Daigo Ohtoyo

Kazuya Saitoh

Norio Uemura

Keisuke Inoue

Taku Hirosawa

Shigeru Taniguchi

Satoshi Kohiki

Hisashi Mitsunaga

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 cycle is repeated a plurality of times, which includes a forging process for placing a material to be forged in a lower die and pressing the material to be forged in this state and then separating an upper die from the material to be forged; an elevation process for lifting the material to be forged by using an elevation device to separate the material to be forged from the lower die; a rotation process for rotating the material to be forged around its center by using a rotation device; and a lowering process for placing the material to be forged rotated by the elevation device in the lower die.

Method and apparatus for producing forging by rotary forging

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

A sputter target material which is of a sintered material, wherein the sputter target material consists of 0.5 to 50 atomic % in total of at least one metal element (M) selected from the group of Ti, Zr, V, Nb and Cr, and the balance of Mo and unavoidable impurities, and has a microstructure seen at a perpendicular cross section to a sputtering surface, in which microstructure oxide particles exist near a boundary of each island of the metal element (M), and wherein the maximum area of the island, which is defined by connecting the oxide particles with linear lines so as to form a closed zone, is not more than 1.0 mm.

Method of producing a sputter target material

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Yasugi, Japan

Tsuyoshi Fukui