Copper-alloy stainless pipe, air conditioner including the same, and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-11834735-B2
Application number	US-201916395106-A
Country	US
Kind code	B2
Filing date	Apr 25, 2019
Priority date	Dec 19, 2018
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

Disclosed herein are a copper-alloy stainless pipe, an air conditioner including the same and a method of manufacturing the same. A copper-alloy stainless pipe includes a recrystallization layer forming an interface between a pipe base material and a copper plating layer, thereby increasing bonding force between the pipe base material and the copper plating layer. Accordingly, it is possible to prevent the copper plating layer from being peeled off and to increase corrosion resistance of the pipe. The recrystallization layer may be composed of intermetallic compound.

First claim

What is claimed is:

1. A copper-alloy stainless pipe comprising:
a pipe base material composed of stainless steel;
a copper plating layer disposed on an outer surface of the pipe base material; and
a recrystallization layer composed of an intermetallic compound, the recrystallization layer forming an interface between the pipe base material and the copper plating layer,
wherein the recrystallization layer is formed by performing heat treatment in a state in which the copper plating layer is disposed on the pipe base material,
wherein the stainless steel has a ferrite matrix structure that is heat treated between 800° C. to 900° C.,
wherein the stainless steel is composed of 0.03 wt. % or less of Carbon, greater than 0 to 1.7 wt. % or less of Silicon, 1.5 to 3.5 wt. % of Manganese, 15.0 to 18.0 wt. % of Chromium, 7.0 to 9.0 wt. % of Nickel, 1.0 to 4.0 wt. % of Copper, 0.03 wt. % or less of Molybdenum, 0.04 wt. % or less of Phosphorus, 0.04 wt. % or less of Sulfur and 0.03 wt. % or less of Nitrogen,
wherein the intermetallic compound comprises copper (Cu), chromium (Cr), iron (Fe), and nickel (Ni),
wherein a weight percent of chromium (Cr), iron (Fe) and nickel (Ni) in the recrystallization layer decreases in a direction from the pipe base material toward the copper plating layer, and
wherein a weight percent of copper (Cu) in the recrystallization layer increases in a direction from the pipe base material toward the copper plating layer.

2. The copper-alloy stainless pipe of claim 1 , wherein the weight percent of chromium (Cr), iron (Fe) and nickel (Ni) in the recrystallization layer linearly decreases in the direction from the pipe base material toward the copper plating layer.

3. The copper-alloy stainless pipe of claim 1 , wherein the weight percent of copper (Cu) in the recrystallization layer linearly increases in the direction from the pipe base material toward the copper plating layer.

4. The copper-alloy stainless pipe of claim 1 , wherein a thickness of the recrystallization layer in a radial direction is 0.18 μm to 0.22 μm.

5. The copper-alloy stainless pipe of claim 1 , wherein the copper plating layer is composed of copper cyanide or copper sulfate.

6. The copper-alloy stainless pipe of claim 5 , wherein a thickness of the copper plating layer in a radial direction is 3 μm to 30 μm.

7. The copper-alloy stainless pipe of claim 5 , wherein a thickness of the copper plating layer in a radial direction is 3 μm to 5 μm.

8. An air conditioner comprising a compressor, an outdoor unit including a suction pipe connected to an inlet side of the compressor and a discharge pipe connected to an outlet side of the compressor, and an indoor unit connected to the outdoor unit,
wherein the suction pipe or the discharge pipe comprises a copper-alloy stainless pipe welded to a copper pipe,
wherein the copper-alloy stainless pipe comprises:
a pipe base material composed of stainless steel;
a copper plating layer disposed on an outer surface of the pipe base material; and
a recrystallization layer composed of intermetallic compound, the recrystallization layer forming an interface between the pipe base material and the copper plating layer,
wherein the recrystallization layer is formed by performing heat treatment in a state in which the copper plating layer is disposed on the pipe base material,
wherein the stainless steel has a ferrite matrix structure that is heat treated between 800° C. to 900° C.,
wherein the stainless steel is composed of 0.03 wt. % or less of Carbon, greater than 0 to 1.7 wt. % or less of Silicon, 1.5 to 3.5 wt. % of Manganese, 15.0 to 18.0 wt. % of Chromium, 7.0 to 9.0 wt. % of Nickel, 1.0 to 4.0 wt. % of Copper, 0.03 wt. % or less of Molybdenum, 0.04 wt. % or less of Phosphorus, 0.04 wt. % or less of Sulfur and 0.03 wt. % or less of Nitrogen,
wherein the intermetallic compound comprises copper (Cu), chromium (Cr), iron (Fe), and nickel (Ni),
wherein a weight percent of chromium (Cr), iron (Fe) and nickel (Ni) in the recrystallization layer decreases in a direction from the pipe base material toward the copper plating layer, and
wherein a weight percent of copper (Cu) in the recrystallization layer increases in a direction from the pipe base material toward the copper plating layer.

9. The air conditioner of claim 8 ,
wherein the copper-alloy stainless pipe is bonded to an inside surface of the copper pipe, and
wherein a welding portion is formed between the copper-alloy stainless pipe and the copper pipe.

10. The air conditioner of claim 9 , wherein the welding portion comprises a filler metal.

11. A method of manufacturing a copper-alloy stainless pipe comprising:
plating an outer surface of a pipe base material composed of stainless steel with copper to form a copper plating layer; and
performing a recrystallization process of the pipe base material and the copper playing layer by heat treating the pipe base material and the copper plating layer to form a recrystallization layer between the pipe base material and the copper plating layer,
wherein the recrystallization layer is formed by performing heat treatment in a state in which the copper plating layer is disposed on the pipe base material,
wherein the stainless steel has a ferrite matrix structure that is heat treated between 800° C. to 900° C.,
wherein the stainless steel is composed of 0.03 wt. % or less of Carbon, greater than 0 to 1.7 wt. % or less of Silicon, 1.5 to 3.5 wt. % of Manganese, 15.0 to 18.0 wt. % of Chromium, 7.0 to 9.0 wt. % of Nickel, 1.0 to 4.0 wt. % of Copper, 0.03 wt. % or less of Molybdenum, 0.04 wt. % or less of Phosphorus, 0.04 wt. % or less of Sulfur and 0.03 wt. % or less of Nitrogen,
wherein the intermetallic compound comprises copper (Cu), chromium (Cr), iron (Fe), and nickel (Ni),
wherein a weight percent of chromium (Cr), iron (Fe) and nickel (Ni) in the recrystallization layer decreases in a direction from the pipe base material toward the copper plating layer, and
wherein a weight percent of copper (Cu) in the recrystallization layer increases in a direction from the pipe base material toward the copper plating layer.

12. The method of claim 11 , wherein the copper-alloy stainless pipe is welded to a copper pipe to form a refrigerant pipe.

13. The method of claim 11 , wherein the heat treating is performed for a set time of 10 to 20 minutes.

Assignees

• Lg Electronics Inc

Inventors

• Hong Seokpyo

Classifications

• C22C38/58 Primary

  with more than 1.5% by weight of manganese · CPC title

• B23K35/302

  Cu as the principal constituent · CPC title

• C21D9/08

  for tubular bodies or pipes · CPC title

• C22C38/001

  containing N · CPC title

• C22C38/02

  containing silicon · CPC title