ALUMINIUM ALLOY FLAT TUBE FOR HEAT EXCHANGER AND METHOD FOR MANUFACTURING THE SAME, AND HEAT EXCHANGER CORE AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide: an aluminium alloy flat tube for heat exchangers, capable of obtaining a heat exchanger excellent in corrosion resistance even when a brazing heating time is reduced in order to improve the mass productivity of the heat exchanger; a method for manufacturing the aluminium alloy flat tube for heat exchangers; the heat exchanger excellent in corrosion resistance; and a method for manufacturing the heat exchanger.SOLUTION: The method for manufacturing the aluminium alloy flat tube for heat exchangers comprises: superimposing the flat surface of a Zn sprayed element tube having a Zn sprayed layer of 5-20 g/mon the flat surface of an extruded flat tube formed of aluminium alloy consisting of Cu of 0.1-0.7 mass% and the remainder of aluminum and inevitable impurities; and performing a preliminary diffusion heat treatment so that the maximum arrival temperature is 430-550°C, and the total diffusion amount of Zn ΣDt shown in the following formula (1) is in a range of 0.8×10to 4.6×10(m). ΣDt=ΣD×exp (-Q/(R-Tn))×Δtn (1).SELECTED DRAWING: Figure 8