Highly corrosion resistant copper tube

Abstract

The purpose of the present invention is to provide a copper pipe that is capable of exhibiting higher corrosion resistance with respect to formicary corrosion, can be suitably used in air conditioners and freezing equipment, and has excellent long-term anti-corrosion properties, and to advantageously improve the service life of equipment configured using such copper pipe. The copper pipe is configured from a material, which contains P (phosphorus) in a proportion of 0.15-0.50 weight %, in which oxygen content is 30 ppm by weight or less, and the balance is made of Cu and unavoidable impurities.

1 . A highly corrosion-resistant copper tube which is formed of a copper material comprising a copper alloy consisting of 0.15-0.50% by weight of phosphorus and the balance being copper and inevitable impurities, the copper material having an oxygen content of not higher than 30 ppm by weight. 
     
     
         2 . The highly corrosion-resistant copper tube according to  claim 1 , wherein the oxygen content of the copper material is not higher than 20 ppm by weight. 
     
     
         3 . The highly corrosion-resistant copper tube according to  claim 1 , wherein a total amount of the inevitable impurities is not higher than 0.05% by weight. 
     
     
         4 . The highly corrosion-resistant copper tube according to  claim 2 , wherein a total amount of the inevitable impurities is not higher than 0.05% by weight. 
     
     
         5 . The highly corrosion-resistant copper tube according to  claim 1 , wherein the copper tube is arranged in a damp environment and subjected to corrosion that progresses in the form of an ants' nest from a surface of the tube in a direction of a wall thickness of the tube by a corrosive medium in the form of a lower carboxylic acid. 
     
     
         6 . A heat transfer tube for air-conditioning equipment or refrigerating equipment, consisting of the highly corrosion-resistant copper tube according to  claim 1 . 
     
     
         7 . A refrigerant tube for air-conditioning equipment or refrigerating equipment, consisting of the highly corrosion-resistant copper tube according to  claim 1 . 
     
     
         8 . A method of improving a corrosion resistance of a copper tube against ant nest corrosion which is generated by a corrosive medium in the form of a lower carboxylic acid in a damp environment and progresses from a surface of the copper tube used for air-conditioning equipment or refrigerating equipment in the damp environment, wherein
 the copper tube is formed of a copper material comprising a copper alloy consisting of 0.15-0.50% by weight of phosphorus and the balance being copper and inevitable impurities, the copper material having an oxygen content of not higher than 30 ppm by weight.