PURPOSE: To improve corrosion resistance by coating Zn on the surface of an extruded pipe of Al or Al alloy and further flame-spraying Al or Al alloy as a second layer.

CONSTITUTION: Zn, which is coated as a second layer, is used to provide a diffusion layer of Zn on the surface of a pipe by means of brazing heating. Preferably, the amount of Zn adhesion should range 3W30g/m2. The role of the second layer which is produced by film- spraying Al or Al alloy, is to prevent the evaporation of Zn coated on the first layer. With regards to a pipe member on which only Zn is coated as a first layer, the amount of Zn is evaporated by 80%, if an attempt is made to carry out vacuum brazing. Due to the evaporation of Zn, a diffusion layer whose maximum Zn concentration is 0.3% and below can be produced on the surface of the pipe, which results in degraded corrosion resistance. To solve this problem, an attempt is made to coat the surface of the pipe with Zn as a first layer 5 and film-spray Al or Al alloy all over the Zn coated pipe surface as a second layer 6. With regards to Al or Al alloy, which serves as the second layer, as attempt is made to select such Al or Al alloy so as to prevent the potential of the Zn diffusion layer on the surface of the pipe after brazing from becoming negative. Especially, if an attempt is made to film-spray the Al-Ca alloy or Al-Zn-Ca alloy over the pipe surface as the second layer, the evaporation of Zn can be further controlled.