Aluminum alloy fin material for heat exchanger, method for manufacturing same, heat exchanger using said aluminum alloy fin material and method for manufacturing same

Abstract

There are provided: an aluminum alloy fin material for a heat exchanger, the aluminum alloy fin material including an aluminum alloy including 0.70 to 1.50 mass % Si, 0.05 to 2.00 mass % Fe, 1.0 to 2.0 mass % Mn, 0.5 to 4.0 mass % Zn, with a balance consisting of Al and inevitable impurities, in which before brazing heating, the amount of solid solution Si is 0.60 mass % or less, and the amount of solid solution Mn is 0.60 mass % or less, and in which a recrystallization temperature in a temperature rise process during the brazing heating is 450° C. or less; a method of producing the aluminum alloy fin material; a heat exchanger using the aluminum alloy fin material; and a method of producing the heat exchanger.

1 . An aluminum alloy fin material for a heat exchanger, the aluminum alloy fin material comprising an aluminum alloy comprising 0.70 to 1.50 mass % Si, 0.05 to 2.00 mass % Fe, 1.0 to 2.0 mass % Mn, 0.5 to 4.0 mass % Zn, with a balance consisting of Al and inevitable impurities, wherein before brazing heating, an amount of solid solution Si is 0.60 mass % or less, and an amount of solid solution Mn is 0.60 mass % or less, and wherein a recrystallization temperature in a temperature rise process during the brazing heating is 450° C. or less. 
     
     
         2 . The aluminum alloy fin material for a heat exchanger according to  claim 1 , wherein in the aluminum alloy after brazing heating, an amount of solid solution Mn is 0.60 mass % or less, and each of values of S1/S2 and Z1/Z2 is 1.20 or less when concentrations of Si and Zn in a vicinity of a grain boundary are assumed to be S1 mass % and Z1 mass %, respectively, and concentrations of Si and Zn in a matrix are assumed to be S2 mass % and Z2 mass %, respectively. 
     
     
         3 . The aluminum alloy fin material for a heat exchanger according to  claim 1 , wherein the aluminum alloy further comprises one or more selected from 0.05 to 0.30 mass % Cu, 0.05 to 0.30 mass % Ti, 0.05 to 0.30 mass % Zr, 0.05 to 0.30 mass % Cr, and 0.05 to 0.30 mass % V. 
     
     
         4 . A method of producing the aluminum alloy fin material for a heat exchanger according to  claim 1 , the method comprising a step of casting the aluminum alloy, a hot-rolling step of hot-rolling a cast ingot, a cold-rolling step of cold-rolling a hot-rolled sheet, and one or more annealing steps of annealing a cold-rolled sheet in or after the cold-rolling step, or in and after the cold-rolling step, wherein the hot-rolling step comprises a heating stage, a retention stage, and a hot-rolling stage, wherein in the heating stage, a heating rate from attainment of 400° C. to attainment of a retention temperature in the retention stage is 60° C./h or less, wherein in the retention stage, the retention temperature is 450 to 560° C., and a retention time is 0.5 hour or more, wherein in the hot-rolling stage, a time for which the hot-rolled sheet has a temperature of 400° C. or more is 5 minutes or more, and wherein in the cold-rolling step, the cold-rolled sheet has a temperature of 120° C. or less. 
     
     
         5 . A method of producing the aluminum alloy fin material for a heat exchanger according to  claim 1 , the method comprising a step of casting the aluminum alloy, a homogenization treatment step of homogenization-treating a cast ingot, a hot-rolling step of hot-rolling a homogenization-treated ingot, a cold-rolling step of cold-rolling a hot-rolled sheet, and one or more annealing steps of annealing a cold-rolled sheet in or after the cold-rolling step, or in and after the cold-rolling step, wherein the homogenization treatment step comprises a heating stage, a retention stage, and a cooling stage, wherein in the heating stage, a heating rate from attainment of 400° C. to attainment of a retention temperature in the retention stage is 60° C./h or less, wherein in the retention stage, the retention temperature is 450 to 560° C., and a retention time is 1.0 hour or more, wherein in the cooling stage, a cooling rate before the ingot attains a temperature of 400° C. is 60° C./h or less, and wherein in the cold-rolling step, the cold-rolled sheet has a temperature of 120° C. or less. 
     
     
         6 . A heat exchanger to which the aluminum alloy fin material according to  claim 1  is assembled by brazing. 
     
     
         7 . A method of producing the heat exchanger according to  claim 6 , the method comprising subjecting a combination of the aluminum alloy fin material according to  claim 1  with another member to brazing heating at an attainment temperature of 590 to 615° C. for 2 to 6 minutes, wherein a recrystallization temperature in a temperature rise process during brazing is set at 450° C. or less, and a heating rate in a temperature range of 300 to 580° C. is set at 60 to 160° C./min.