Patent ID: 6715667
Filing Date: 2004-04-06
Classification: B23K,Y10T

Abstract:
A method of joining a steel tube with an aluminum rib, comprising the steps of:applying a layer of a zinc-aluminum alloy with an aluminum content of 0.5% by wt. to 20% by wt. onto a surface of a steel tube or aluminum rib; depositing a fluxing agent in the form of cesium-aluminum tetrafluoride between the steel tube and the aluminum rib at room temperature in one of the phases selected from the group consisting of before and during mechanical contact of the aluminum rib with the steel tube; heating the steel tube provided with the aluminum rib in a furnace to a soldering temperature between 370Â° C. and 470Â° C.; and exposing the steel tube provided with the aluminum rib to room temperature to cool down, wherein the aluminum rib is wound onto the steel tube in a helical manner, wherein the fluxing agent is deposited onto the surface of the steel tube at a leading engagement point of the aluminum rib upon the steel tube before the aluminum rib is attached onto the steel tube.