Aluminum alloy extruded multi-hole tube for heat exchanger and method for manufacturing the same

A method for manufacturing an aluminum alloy extruded multi-hole tube for a heat exchanger, the method comprising:

• two-step homogenization treatment of executing first homogenization treatment of heating an ingot at a heating temperature of 550 to 650° C. for 2 hours or more, followed by second homogenization treatment of heating the ingot at a heating temperature of 450 to 540° C. for 3 hours or more, to set electrical conductivity change (electrical conductivity (C) of the ingot after the second homogenization treatment−electrical conductivity (D) of the ingot before the first homogenization treatment) before and after the two-step homogenization treatment to 20% IACS or more, the ingot being formed of an aluminum consisting of Mn of 1.20 to 1.80 mass % and Si of 0.40 to 0.70 mass %, optionally one or more selected from Ti of 0.10 mass % or less, and Cu of 0.05 mass % or less, with the balance being Al and inevitable impurities, the aluminum alloy having a ratio (Mn/Si) of Mn content to Si content being 2.6 to 3.0, and
• a hot extrusion step of executing hot extrusion of the treated material of the two-step homogenization treatment at a heating temperature at which an absolute value of a difference (heating temperature during hot extrusion−heating temperature of the second homogenization treatment) between the heating temperature during hot extrusion and the heating temperature of the second homogenization treatment is 50° C. or less.