MULTI-LAYERED BRAZING SHEET

摘要

The invention pertains to a multi-layered brazing sheet with improved long life corrosion resistance which is achieved by balancing the Zn, Cu, Mn, Si and Mg content of the core and interliner alloy. To this end the brazing sheet comprises a core of a 3xxx alloy, an inner braze cladding of a 4xxx alloy , and between core and inner braze cladding an interliner of a 3xxx alloy, wherein the 3xxx alloy of the core comprises 0.55 - 1.0 wt% Cu, 0.7 - 1.8 wt% Mn, < 0.3 wt% Mg, < 0.4 wt% Zn and the 3xxx alloy of the interliner < 0.25 wt% Cu, 0.5 - 1.5 wt% Mn, < 0.3 wt% Mg, 0.1- 5.0 wt% Zn . Instead of a 3xxx alloy also a lxxx or 7xxx alloy could be used for the interliner.