To provide a heat exchanger and its manufacturing method capable of reducing influence of a brazing filler metal applied to an outer face of a tube on a sacrificial corrosion layer.
The tube 30 is composed of a first core material part 35 having a plurality of projecting and recessed portions, and a second core material part 45 having a plurality of projecting and recessed portions and defining an internal passage 33 with the first core material part. Both core material parts are brazed by inner brazing filler metal layers 43, 53 formed between an inner projecting portion 41 and an inner projecting portion 51. The sacrificial corrosion layers 55, 61 are cladded on outer faces of both core material parts, and outer brazing filler metal layers 57, 63 are applied on the sacrificial corrosion layers 55a, 61a of the outer face projecting portions 37, 47. Fins 65 are brazed to the outer face projecting portion and the outer face projecting portion by the outer brazing filler metal layers.
HASEGAWA YOSHIHARU
TOYAMA TAKETOSHI
