Patent ID: 7377418
Filing Date: 2008-05-27
Classification: B23K,F27B,F27D

Abstract:
1. A method for brazing aluminum products, comprising: a) providing a heating furnace including a preheating furnace having carbonaceous walls; b) providing the preheating furnace before the heating furnace; c) providing a fan configured for convectively fanning a gas in the preheating furnace; d) preliminarily heating up aluminum products which are to be conveyed into the heating furnace through its preheating furnace, the aluminum products being preliminarily heated up in the preheating furnace immediately before they are brazed in the heating furnace, and near to a brazing temperature of aluminum products of 500-630° C.; and e) introducing into the gas in the preheating furnace a neutral nitrogen gas which is heated and fanned convectively in the preheating furnace having the carbonaceous walls, whereby its oxygen partial pressure is kept sufficiently low so that there is substantially no observable oxidation on the resultant preheated aluminum products, preheated but before-melting fluxes, and preheated but before-melting solders each applied on the resultant preheated aluminum products.