4号合金是立足国内资源、自行设计研制成功的一种新型高温钎焊合金。填补了我国钎温为1065～1080℃箔材钎料的空白,并为建立我国锰基高温钎焊合金系统提供了有益的经验。主要化学成份如下:Mn 50±1% Ni 27.5±1%Cu 13.5±0.5% Cr 4.5±0.5% Alloy 4 is based on domestic resources, self-designed and developed a new type of high-temperature brazing alloy. It has filled up the blank of foil brazing material with 1065 ~ 1080 ℃ brazing temperature in our country, and provided useful experience for establishing the manganese-based brazing alloy system in China. The main chemical composition is as follows: Mn 50 ± 1% Ni 27.5 ± 1% Cu 13.5 ± 0.5% Cr 4.5 ± 0.5%