摘要:
In order to realize a joint structure for metallic pipes which is capable of suppressing cost increase while suppressing a deterioration in reliability of a joint portion between metallic pipes, the present invention provides a joint structure for metallic pipes in which: one of a first metallic pipe (11) containing a first metal (M1) as a main component and a second metallic pipe (12) containing a second metal (M2) as a main component includes an expanded-diameter connecting part (13) which is formed at an end part of the one metallic pipe, an inner diameter of the end part is greater than an inner diameter of an adjacent part (16) that is adjacent to the end part; an intermetallic compound layer (15) of the first metal (M1) and the second metal (M2) is present at an interface of the first metal (M1) and the second metal (M2) located between a brazing filler metal (14) and the one or the other of the metallic pipes; and a thickness of the intermetallic compound layer (15) is configured such that the thickness of an end portion (15b) on the side of a base end (13b) is smaller than the thickness of an end portion (15a) on the side of an open end (13a).