MULTI-LAYERED BRAZING SHEET

摘要

A multi-layered brazing sheet with improved long life corrosion resistance achieved by balancing the Zn, Cu, Mn, Si and Mg content of the core and interliner alloy. The brazing sheet has 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. The 3xxx alloy of the core has 0.55-1.0 wt % Cu, 0.7-1.8 wt % Mn, <0.3 wt % Mg, <0.4 wt % Zn. The 3xxx alloy of the interliner has <0.25 wt % Cu, 0.5-1.5 wt % Mn, <0.3 wt % Mg, 0.1-5.0 wt % Zn. A 1xxx or 7xxx alloy could be used for the interliner instead of the 3xxx alloy.