Highly corrosion-resistant copper tube

Abstract

Use of a heat transfer tube in a damp environment in air-conditioning equipment and exposed to corrosive action caused by a corrosive medium comprising at least one lower carboxylic acid, the heat transfer tube a copper tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities. The corrosive action progresses in the form of an ants' nest from an outer surface of the heat transfer tube in a direction of its wall thickness, wherein. Also, use of a copper tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities for improving corrosion-resistance against ant nest corrosion caused by a corrosive medium consisting of a lower carboxylic acid in a damp environment, method of inhibiting ants' nest corrosion in a heat transfer tube, and a method of positioning a tube in an air conditioning apparatus or a refrigeration apparatus.

1 . Use of a heat transfer tube used in a damp environment in air-conditioning equipment and exposed to a corrosive action caused by a corrosive medium comprising at least one lower carboxylic acid, which corrosive action progresses in the form of an ants' nest from an outer surface of the heat transfer tube in a direction of its wall thickness, wherein the heat transfer tube is a copper tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities. 
     
     
         2 . The use of a heat transfer tube as recited in  claim 1 , wherein the heat transfer tube comprises not lower than 0.15% by weight of P. 
     
     
         3 . The use of a heat transfer tube as recited in  claim 1 , wherein the heat transfer tube comprises not higher than 0.8% by weight of P. 
     
     
         4 . The use of a heat transfer tube as recited in  claim 1 , wherein the heat transfer tube comprises not higher than 0.5% by weight of P. 
     
     
         5 . The use of a heat transfer tube as recited in  claim 1 , wherein the heat transfer tube comprises 0.3-1.0% by weight of P. 
     
     
         6 . The use of a heat transfer tube as recited in  claim 1 , wherein the heat transfer tube comprises not lower than 0.19% by weight of P. 
     
     
         7 . The use of a heat transfer tube as recited in  claim 1 , wherein a total amount of the inevitable impurities is not higher than 0.05% by weight. 
     
     
         8 . The use of a heat transfer tube as recited in  claim 1 , further comprising operating said air conditioning equipment such that heat is transferred through said heat transfer tube. 
     
     
         9 . The use of a heat transfer tube as recited in  claim 1 , wherein corrosion progresses in a direction extending along a surface of the heat transfer tube. 
     
     
         10 . The use of a heat transfer tube as recited in  claim 1 , wherein the heat transfer tube was produced by casting an ingot or a billet, and extruding and drawing the ingot or billet. 
     
     
         11 . Use of a copper tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities for improving corrosion-resistance against ant nest corrosion caused by a corrosive medium consisting of a lower carboxylic acid in a damp environment. 
     
     
         12 . The use of a heat transfer tube as recited in  claim 11 , wherein the heat transfer tube comprises not lower than 0.15% by weight of P. 
     
     
         13 . The use of a heat transfer tube as recited in  claim 11 , wherein the heat transfer tube comprises not higher than 0.8% by weight of P. 
     
     
         14 . The use of a heat transfer tube as recited in  claim 11 , wherein the heat transfer tube comprises not higher than 0.5% by weight of P. 
     
     
         15 . The use of a heat transfer tube as recited in  claim 11 , wherein the heat transfer tube comprises 0.3-1.0% by weight of P. 
     
     
         16 . The use of a heat transfer tube as recited in  claim 11 , wherein the heat transfer tube comprises not lower than 0.19% by weight of P. 
     
     
         17 . The use of a heat transfer tube as recited in  claim 11 , wherein a total amount of the inevitable impurities is not higher than 0.05% by weight. 
     
     
         18 . The use of a heat transfer tube as recited in  claim 11 , further comprising operating said air conditioning equipment such that heat is transferred through said heat transfer tube. 
     
     
         19 . The use of a heat transfer tube as recited in  claim 11 , wherein corrosion progresses in a direction extending along a surface of the heat transfer tube. 
     
     
         20 . The use of a heat transfer tube as recited in  claim 11 , wherein the heat transfer tube was produced by casting an ingot or a billet, and extruding and drawing the ingot or billet. 
     
     
         21 . A method of inhibiting ants' nest corrosion in a heat transfer tube, the method comprising:
 forming a tube having a composition comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities;   positioning the tube in an air conditioning apparatus or a refrigeration apparatus; and   subjecting the tube to a corrosive environment comprising at least one lower carboxylic acid in a damp atmosphere.   
     
     
         22 . A method, comprising:
 positioning a tube in an air conditioning apparatus or a refrigeration apparatus;   operating said air conditioning apparatus or refrigeration apparatus such that heat is transferred through said tube; and   exposing said tube to a corrosive medium in a damp environment in said air-conditioning apparatus or said refrigeration apparatus, such that said corrosive medium generates ants' nest corrosion that progresses from a surface of said tube,   said tube comprising 0.10-1.0% by weight of P and the balance consisting of Cu and inevitable impurities.