Novel copper alloy and copper alloy pipe

Abstract

The invention provides copper alloy with excellent tensile strength and a copper alloy pipe prepared from the copper alloy. The copper alloy comprises 0.15 to 0.95 mass percent of Sn, 0.01 to 0.060 mass percent of P, 0.001 to 0.01 mass percent of B and the balance of copper and other impurities, wherein the impurity content is less than 0.06 mass percent. The longitudinal tensile strength sigmab of the annealed copper alloy pipe is more than or equal to 250 N / mm<2>, the radial average grain is less than or equal to 0.035 millimeter, and a yield ratio of the yield (limit) strength sigma 0.2 of a longitudinal tensile test to sigma b is less than or equal to 0.27. Compared with the copper alloy pipe made of phosphorus deoxidized copper, the tensile strength is improved, grains are refined, the yield strength is not changed obviously, and the corrosion resistance and heat resistance are excellent.

Description

technical field [0001] The invention relates to a copper-based alloy, in particular to a high-strength copper alloy and a copper alloy tube prepared from the copper alloy. Background technique [0002] Usually, phosphorus deoxidized copper (TP2) is mostly used in heat exchangers (evaporators, condensers), connecting pipes (for indoor and outdoor connection) and various copper alloy pipes for refrigeration and air conditioning, because phosphorus deoxidized copper has good thermal conductivity. , and good plasticity, easy processing and welding. [0003] At present, in the air-conditioning refrigerant market, most developing countries use HCFC (hydrochlorofluorocarbon) Freon. Taking this series of R22 as an example, the maximum working pressure of the pipeline is 1.5MPa, and R22 has a relatively large damage coefficient to the earth's atmospheric ozone layer. . However, some developed countries such as Europe, America, and Japan have begun to fully use HFC-based freon with ...

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Problems solved by technology

[0004] In addition, in the process of making air-conditioning heat exchangers, the copper alloy tubes for refrigeration need to undergo three processes of bending, expanding and flaring, and the hairpin tubes made of copper alloy tubes for refrigeration must be flared with small U-shaped elbow welding, the welding temperature is 750 ~ 850 ° C, after heating, the local grain grows and the strength decreases, which objectively increases the probability of cracking from the weld.

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