Method of manufacturing Ni-base superalloy

Patent metadata

Field	Value
Publication number	US-9909200-B2
Application number	US-201515512458-A
Country	US
Kind code	B2
Filing date	Sep 29, 2015
Priority date	Sep 29, 2014
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

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 μm 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.

First claim

The invention claimed is:

1. A method of manufacturing an Ni-base superalloy, in which a forging stock including an Ni-base superalloy, coated with a lubricant, is subjected to hot forging, comprising:
a preliminary oxidation step of previously generating a Cr oxide coating film having a film thickness of 0.5 to 50 μm on the forging stock;
a lubricant coating step of coating a Cr oxide coating film formed on the forging stock having been subjected to the preliminary oxidation step with a glass lubricant including borosilicate glass as a main component; and
a hot forging step of hot forging the forging stock having been subjected to the lubricant coating step.

2. The method of manufacturing an Ni-base superalloy according to claim 1 , wherein a thickness of the glass lubricant applied in the lubricant coating step is 100 to 600 μm.

3. The method of manufacturing an Ni-base superalloy according to claim 1 , wherein a heating temperature in the preliminary oxidation step is 900° C. to a hot forging temperature.

4. The method of manufacturing an Ni-base superalloy according to claim 1 , wherein the Ni-base superalloy contains, in terms of mass %, 0.08% or less of C, 0.35% or less of Si, 0.35% or less of Mn, 0.015% or less of P, 0.015% or less of S, 50.0 to 55.0% of Ni, 17.0 to 21.0% of Cr, 2.8 to 3.3% of Mo, 1.0% or less of Co, 0.30% or less of Cu, 0.20 to 0.80% of Al, 0.65 to 1.15% of Ti, 4.75 to 5.50% of Nb+Ta, 0.006% or less of B, and a remainder of Fe and unavoidable impurities.

5. The method of manufacturing an Ni-base superalloy according to claim 1 , wherein the hot forging step is closed die forging using a die heated to a temperature of 400° C. or higher.

6. The method of manufacturing an Ni-base superalloy according to claim 5 , wherein a heating temperature in the preliminary oxidation step is 900° C. to a hot forging temperature.

7. The method of manufacturing an Ni-base superalloy according to claim 5 , wherein a thickness of the glass lubricant applied in the lubricant coating step is 100 to 600 μm.

8. The method of manufacturing an Ni-base superalloy according to claim 5 , wherein in the hot forging step the forging stock heated to a temperature of 900 to 1100° C. is subjected to hot forging.

9. The method of manufacturing an Ni-base superalloy according to claim 8 , wherein a heating temperature in the preliminary oxidation step is 900° C. to a hot forging temperature.

10. The method of manufacturing an Ni-base superalloy according to claim 8 , wherein the Ni-base superalloy contains, in terms of mass %, 0.08% or less of C, 0.35% or less of Si, 0.35% or less of Mn, 0.015% or less of P, 0.015% or less of S, 50.0 to 55.0% of Ni, 17.0 to 21.0% of Cr, 2.8 to 3.3% of Mo, 1.0% or less of Co, 0.30% or less of Cu, 0.20 to 0.80% of Al, 0.65 to 1.15% of Ti, 4.75 to 5.50% of Nb+Ta, 0.006% or less of B, and a remainder of Fe and unavoidable impurities.

11. The method of manufacturing an Ni-base superalloy according to claim 5 , wherein the Ni-base superalloy contains, in terms of mass %, 0.08% or less of C, 0.35% or less of Si, 0.35% or less of Mn, 0.015% or less of P, 0.015% or less of S, 50.0 to 55.0% of Ni, 17.0 to 21.0% of Cr, 2.8 to 3.3% of Mo, 1.0% or less of Co, 0.30% or less of Cu, 0.20 to 0.80% of Al, 0.65 to 1.15% of Ti, 4.75 to 5.50% of Nb+Ta, 0.006% or less of B, and a remainder of Fe and unavoidable impurities.

12. The method of manufacturing an Ni-base superalloy according to claim 1 , wherein in the hot forging step the forging stock heated to a temperature of 900 to 1100° C. is subjected to hot forging.

13. The method of manufacturing an Ni-base superalloy according to claim 12 , wherein a thickness of the glass lubricant applied in the lubricant coating step is 100 to 600 μm.

14. The method of manufacturing an Ni-base superalloy according to claim 12 , wherein a heating temperature in the preliminary oxidation step is 900° C. to a hot forging temperature.

15. The method of manufacturing an Ni-base superalloy according to claim 12 , wherein the Ni-base superalloy contains, in terms of mass %, 0.08% or less of C, 0.35% or less of Si, 0.35% or less of Mn, 0.015% or less of P, 0.015% or less of S, 50.0 to 55.0% of Ni, 17.0 to 21.0% of Cr, 2.8 to 3.3% of Mo, 1.0% or less of Co, 0.30% or less of Cu, 0.20 to 0.80% of Al, 0.65 to 1.15% of Ti, 4.75 to 5.50% of Nb+Ta, 0.006% or less of B, and a remainder of Fe and unavoidable impurities.

Assignees

• Hitachi Metals Ltd

Inventors

• Aoki Chuya
• Ueno Tomonori

Classifications

• C22C19/051

  and Mo or W · CPC title

• B21J3/00

  Lubricating during forging or pressing (lubricating in general F16N) · CPC title

• C21D1/68

  Temporary coatings or embedding materials applied before or during heat treatment · CPC title

• C22F1/10 Primary

  of nickel or cobalt or alloys based thereon · CPC title

• B21J5/025

  Closed die forging · CPC title