铝制板翅式换热器表面锌扩散防腐处理研究

Research for Aluminum Plate-fin Heat Exchanger Surface Zinc Diffusion Anti-corrosive Treatment

铝制板翅式换热器内外通道具有复杂的翅片结构,孔蚀已成为铝制板翅式换热器泄漏的主要原因,几种专业的表面镀锌防腐处理效果不佳,影响了铝制板翅式换热器在更大范围的推广使用。对一种新型的表面锌扩散防腐处理方法应用于铝制板翅式换热器的工艺进行了研究,经过锌扩散工艺处理,锌原子能扩散至换热器母材内层,形成锌铝合金层,在母材内部距表面100μm深度处锌含量可达0.49%。热扩散温度与时间是影响锌扩散的主要因素,当工艺操作温度恒定,时间越长,锌扩散的深度和锌含量就越大。经过锌扩散处理的铝制板翅式换热器耐蚀试验结果表明,锌铝合金层具有优良的防腐蚀效果。

The internal and external channel of the plate - fin heat - exchanger has a complex fin struc- ture. Pitting corrosion has become the main reason of the plate - fin heat exchanger leakage. The effect of several profession surface galvanized anti -corrosion processing methods are proved invalid. For this rea- son,the plate -fin heat exchanger can＇t be used in the wider field. The author discusses a new method of surface zinc diffusion anti - corrosive processing and how to applied it to the plate - fin heat - exchanger technology. After zinc thermal diffusion process, zinc atomic can diffuse to heat - exchanger inner materi- als and form zinc - alloy layer. In the main material, the place to the surface in internal 100 μm the depths zinc density can amount to 0.49%. Thermal diffusion temperature and time are the main factors of influence zinc diffusion. When operation temperature constant and time longer, the depth and density of spread zinc will be greater. After zinc diffusion treatment, the plate -fin heat exchanger corrosion test re- suits show that the zinc alloy layer with excellent anti -corrosion effect.