MONOBRAZE单层翅片箔与三层复合翅片箔耐腐蚀性能对比研究

Contrastive study of corrosion resistance properties of MONOBRAZE bare fin and three-layer clad fin

采用金相显微镜、电位计、EPMA和SWAAT腐蚀试验等手段,研究了分别采用三层复合翅片箔和MONOBRAZE单层翅片箔钎焊后的两种冷凝器接头断面形貌、微观组织、元素扩散、电极电位和耐腐蚀性能。结果表明:与热轧三层复合翅片箔相比,MONOBRAZE单层翅片具有同样的钎焊连接效果,而且钎焊后强度更高、无明显熔蚀、翅片厚度无明显减薄,为MONOBRAZE翅片进一步减薄、大面积替代复合翅片、降低热交换器制造成本创造了有利条件。同时,采用MONOBRAZE单层翅片钎焊后的冷凝器有着更优良的耐腐蚀性能,MONOBRAZE翅片优先被腐蚀,可以对MPE管起到更好的牺牲阳极保护作用,大幅提高热交换器整体寿命。

The cross section morphology,microstructure,elemental diffusion,electrode potential and corrosion resistance of two kinds of condenser joints brazed with three-layer composite fin foil and MONOBRAZE bare fin were studied by means of metallography microscope,potentimeter,EPMA and SWAAT corrosion tests.The result showed that,comparing with three-layer clad fin,MONO⁃BRAZE bare fin has the same brazing connecting effect,with higher tensile strength and without obvious erosion and thickness-re⁃duction after brazing.It is advantageous for thinner MONOBRAZE bare fin to replace clad fin and reduce manufacturing cost of heat exchangers.Moreover,condenser brazed with MONOBRAZE bare fin has more better corrosion resistance property for MONO⁃BRAZE fin is corroded preferentially and it has a better sacrificial anode protection for MPE tube,and life of heat exchangers can be improved largely.