Hitachi Metals, Ltd.

Proterial, Ltd.

Chuya Aoki

Tomonori Ueno

Takehiro Ohno

Shinichi Kobayashi

Etsuo Fujita

Tsuyoshi Fukui

Naoyuki Iwasa

Toshihiro Uehara

Shogo Suzuki

Shinya Nagao

Toshiya Teramae

Remi Mukouse

Tetsuya Yagami

Jun Sato

Yoji Yamashita

Eiji Shimohira

Daigo Ohtoyo

Ryutaro Abe

Taku Hirosawa

Toshiki Ishida

Masayoshi Date

A method for manufacturing a hot-forged member includes heating an unheated material for hot forging in a furnace to a hot forging temperature; bonding a heat-resistant insulation material to at least a part of a surface of a material for forging removed from the furnace to obtain a material to be hot forged; and compressing a part or all of the material to be hot forged into a predetermined shape using any of a die, an anvil, and a tool.

Method for manufacturing hot-forged member

Provided are a Ni-based superalloy for stably obtaining high tensile strength and a method for manufacturing the same. Provided are: a Ni-based superalloy having a composition comprising, in mass %, C: up to 0.10%, Si: up to 0.5%, Mn: up to 0.5%, P: up to 0.05%, S: up to 0.050%, Fe: up to 45%, Cr: 14.0 to 22.0%, Co: up to 18.0%, Mo: up to 8.0%, W: up to 5.0%, Al: 0.10 to 2.80%, Ti: 0.50 to 5.50%, Nb: up to 5.8%, Ta: up to 2.0%, V: up to 1.0%, B: up to 0.030%, Zr: up to 0.10%, Mg: up to 0.005%, and the balance of Ni with inevitable impurities, and has a grain orientation spread (GOS) of at least 0.7&#xb0; as an intragranular misorientation parameter measured by an SEM-EBSD technique; and a method for manufacturing the same.

Ni-based superalloy and method for manufacturing Ni-based superalloy

Provided are a Ni-based alloy for hot die having a high high-temperature compressive strength and a good oxidation resistance and being capable of suppressing the deterioration in the working environment and the shape deterioration, and a hot forging die made of the Ni-based alloy for hot die. The Ni-based alloy for hot die comprises, in mass %, W: 7.0 to 15.0%, Mo: 2.5 to 11.0%, Al: 5.0 to 7.5%, Cr: 0.5 to 3.0%, Ta: 0.5 to 7.0%, S: 0.0010% or less, one or two or more selected from rare-earth elements, Y, and Mg in a total amount of 0 to 0.020%, and the balance of Ni with inevitable impurities. In addition to the composition described above, one or two elements selected from Zr and Hf can further be contained in a total amount of 0.5% or less.

Ni-based alloy for hot-working die, and hot-forging die using same

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 production method for an Fe&#x2014;Ni based heat-resistant superalloy inhibits abnormal grain growth and yields a fine crystal grain structure having an ASTM crystal grain size number of 9 or greater. The production method comprises at least a hot working step in which a material having a prescribed composition is subjected to hot working, wherein the hot working step includes at least a step in which the above material of 930 to 1010&#xb0; C. is subjected to hot working so that the relation of (effective strain)&#x2265;0.139&#xd7;(effective strain rate(/sec))is satisfied in the entirety of the above material.

Production method for Fe-Ni based heat-resistant superalloy

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

There is provided a method of manufacturing an Ni-base superalloy which enables a uniform coat of a glass lubricant to be maintained even after heated to hot forging temperature. The method of manufacturing an Ni-base superalloy in which a forging stock containing an Ni-base superalloy, coated with a lubricant, is subjected to hot forging includes: a preliminary oxidation step of previously generating a Cr oxide coating film having a film thickness of 0.5 to 50 &#x3bc;m on the forging stock thereby to obtain a preliminarily oxidized material; a lubricant coating step of coating the preliminarily oxidized material with a glass lubricant containing borosilicate glass as a main component thereby to obtain a material to be forged; and a hot forging step of hot forging the material to be forged thereby to obtain a hot forged material.

Method of manufacturing Ni-base superalloy

There is provided a method for producing a Ni-based heat-resistant superalloy a primary &#x3b3;' phase with an average particle size of at least 500 nm comprising the steps of: providing a material to be hot-worked having a composition consisting of, by mass, 0.001 to 0.05% C, 1.0 to 4.0% Al, 4.5 to 7.0% Ti, 12 to 18% Cr, 14 to 27% Co, 1.5 to 4.5% Mo, 0.5 to 2.5% W, 0.001 to 0.05% B, 0.001 to 0.1% Zr, and the balance of Ni with inevitable impurities; heating the material to be hot-worked in a temperature having a range of 1,130 to 1,200&#xb0; C. for at least 2 hours; cooling the material to be hot-worked heated by the heating step to a hot working temperature or less at a cooling rate of at most 0.03&#xb0; C./second; and subjecting the material to be hot-worked to hot working after the cooling step.

Ni-based heat-resistant superalloy and method for producing the same

A high-strength Ni-base alloy having favorable corrosion resistance, high strength, and high ductility, around room temperature is provided. A high-strength Ni-base alloy includes: in % by mass, less than 0.01% of C, not more than 0.5% of Si, not more than 0.5% of Mn, 15 to 25% of Cr. 1.0 to 5.0% of Mo or Mo+0.5W, 0.2 to 0.8% of Al, 1.0 to 2.0% of Ti, 3.00 to 3.80% of Nb, not more than 30% of Fe, and 0.0007 to 0.010% of Mg; Ni; and impurities. A value represented by Mg/S is not less than 0.7, and an A value is not less than 0.015 and less than 0.027, the A value being represented by A value=Al/(Al+1.77(Ti&#x2212;1.36C)+3.44(Nb&#x2212;5.1C)).

High-strength Ni-base alloy

There is provided an Ni-base super alloy which is used for airplane engines and gas turbines for power generation and has favorable mechanical properties at high temperature. The Ni-base super alloy contains 0.001 to 0.1 mass % of C, 1.0 to 4.0 mass % of Al, 2.0 to 4.5 mass % of Ti, 12.0 to 18.0 mass % of Cr, 11.1 to 18.0 mass % of Co, 1.2 to 12.0 mass % of Fe, 1.5 to 6.5 mass % of Mo, 0.5 to 6.0 mass % of W, 0.1 to 3.0 mass % of Nb, 0.001 to 0.05 mass % of B, 0.001 to 0.1 mass % of Zr, and Ni and impurities as a remainder.

Ni-base super alloy

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

Provided is an Ni-base alloy excellent in strength, ductility and other properties through the resolution of micro-segregation. Also provided is a process for manufacturing an Ni-base alloy containing by mass C:0.15% or less, Si:1% or less, Mn:1% or less, Cr:10 to 24%, Mo+(1/2)W (where Mo may be contained either alone or as an essential component):5 to 17%, Al:0.5 to 1.8%, Ti:1 to 2.5%, Mg:0.02% or less, and either B:0.02% or less and/or Zr:0.2% or less at an Al/(Al+0.56Ti) ratio of 0.45 to 0.70 with the balance consisting of Ni and impurities, which comprises subjecting, at least one time, an Ni-base alloy material which is prepared by vacuum melting and has the above composition to homogenization heat treatment at 1160 to 1220&#xb0; C. for 1 to 100 hours. The Mo segregation ratio of the alloy is controlled to 1 to 1.17 by the homogenization heat treatment.

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Yasugi, Japan

Chuya Aoki