Impeller brazing method

Patent metadata

Field	Value
Publication number	US-9566655-B2
Application number	US-201113984904-A
Country	US
Kind code	B2
Filing date	Nov 22, 2011
Priority date	Feb 22, 2011
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

The present invention relates to an impeller manufacturing method in which a thermal cycle is performed on an assembly body with a brazing material formed of a Ni-containing Au alloy being placed at a bond portion of at least two impeller constituent members. The thermal cycle includes a temperature increasing process with a temperature increasing rate of 20° C./hr. to 100° C./hr., the process including a first intermediate retention and a second intermediate retention each keeping the temperature, the first intermediate retention performed in a temperature range of 500° C. to 850° C. and the second intermediate retention performed in a temperature range of 850° C. to 950° C. (but not including 850° C.). In the thermal cycle, the temperature is increased in a temperature range exceeding 950° C. after the second intermediate retention at a rate lower than that before the second intermediate retention.

First claim

The invention claimed is:

1. An impeller manufacturing method comprising performing a thermal cycle for bonding on an assembly body with a brazing material interposed at a bond portion between at least two impeller constituent members, wherein the thermal cycle includes:
a temperature increasing process of increasing a temperature to a retention temperature including a first intermediate retention and a second intermediate retention,
wherein, in the temperature increasing process, a temperature increasing rate is 20° C./hr. to 100° C./hr. during the temperature increasing process, but not during the first intermediate retention and the second intermediate retention,
wherein the first intermediate retention is performed in a temperature range of 500° C. to 850° C.,
wherein the second intermediate retention is performed in a temperature range of 850° C. to 950° C., but not including 850° C.,
wherein, in a temperature range exceeding 950° C. after the second intermediate retention, the temperature is increased at a rate slower than a rate before the second intermediate retention;

a retaining process of retaining at the retention temperature in a temperature range equal to or higher than a melting temperature of the brazing material,
wherein, in the retaining process, the retention temperature is selected from a range of 1000° C. to 1050° C.; and

a temperature decreasing process of decreasing the temperature from the retention temperature to a room temperature,
wherein, in the temperature decreasing process, a retention is performed in a temperature range of 930° C. to 970° C., for 0.5 to 2 hours.

2. The impeller manufacturing method according to claim 1 , wherein
in the temperature decreasing process,
a temperature decreasing rate is 20° C./hr. to 100° C./hr., and
from the retention temperature to 950° C., the temperature is decreased at a rate slower than a temperature decreasing rate at a lower temperature.

3. The impeller manufacturing method according to claim 1 , wherein
the thermal cycle is performed with the assembly body being placed with respect to a first heating body heating the assembly body from an inner circumferential side of the assembly body.

4. The impeller manufacturing method according to claim 3 , wherein
the first heating body is integrally provided together with a second heating body supporting the assembly body from below in a vertical direction.

5. The impeller manufacturing method according to claim 3 , wherein
the first heating body satisfies 0.5h 2 ≦h 1 ≦20h 2 ,
where h 1 is a height of the first heating body and h 2 is a height of the assembly body.

6. The impeller manufacturing method according to claim 4 , wherein
the first heating body satisfies 0.5h 2 ≦h 1 ≦20h 2 ,
where h 1 is a height of the first heating body and h 2 is a height of the assembly body.

7. The impeller manufacturing method according to claim 1 , wherein, in the temperature decreasing process, the retention is performed at a temperature of approximately 950° C.

Assignees

• Yokoo Kazutoshi
• Tanaka Daisuke
• Kawada Daisuke
• Niihara Koshiro
• Takagi Hiroki
• Watanabe Yujiro
• Nakajima Hiroshi
• Mitsubishi Heavy Ind Ltd

Inventors

• Yokoo Kazutoshi
• Tanaka Daisuke
• Kawada Daisuke
• Niihara Koshiro
• Takagi Hiroki
• Watanabe Yujiro
• Nakajima Hiroshi

Classifications

• C22C38/04

  containing manganese · CPC title

• B23K1/008

  Soldering within a furnace (B23K1/012 takes precedence) · CPC title

• C22C5/02

  Alloys based on gold · CPC title

• C22C38/42

  with copper · CPC title

• B23K35/3066

  with Ni as next major constituent · CPC title