水源热泵用换热设备常用金属的腐蚀性能

Metal corrosion study on heat exchanger in water source heat pump system

目前有关金属腐蚀的研究多集中在探讨影响腐蚀的因素以及防腐蚀相关技术,有关换热器金属腐蚀经济性的文献较少。本文采用挂片失重试验,结合电镜分析,分别研究了碳钢10#、不锈钢316L、紫铜T2和铝合金LF21在海水和污水中的腐蚀速率、电偶腐蚀速率以及微观腐蚀形貌;并运用模糊综合评价法进行评价,为合理选择换热设备金属材料提供依据。结果表明,根据金属均匀腐蚀耐蚀性十级标准,不锈钢316L、紫铜T2与铝合金LF21都属于耐蚀金属,不锈钢316L在静止和流动水环境中,均具有最好的耐蚀性;在严格避免与电位较正金属偶合使用的前提下,铝合金LF21比碳钢10#和紫铜T2耐蚀,其经济性也较为优秀;碳钢10#虽耐蚀性差但胜在价格优势,是实际工程最常用的金属材料。

Currently,the researches on metal corrosion are mostly focused on factors which affect the corrosion and the anticorrosion technology. The literature on metal corrosion economy of heat exchanger is comparatively less. This paper adopted the loss of mass experiment by hanging metal specimen and the SEM analysis to study the self-corrosion rate and galvanic-corrosion rate of carbon steel 10#,copper T2,stainless steel 316 L and aluminum alloy LF21 in sea water and sewage respectively as well as the micro corrosion morphology. In addition,the use of fuzzy synthetic evaluation method provides the basis for selecting metal materials of heat-exchange equipment reasonably. The results show that copper T2,stainless steel 316 L and aluminum alloy LF21 are all corrosion-resisting metal,and stainless steel 316 L has the best corrosion resistance in both static and flowing water environment. Aluminum alloy LF21 is more corrosion-resistant than carbon steel 10# and copper T2 as long as it is not in a galvanic couple strictly. It is excellent on both corrosion resistance and economy. Although carbon steel 10# is poor in corrosion resistance,it is the most common metal material in the actual project because of its better economical benefits.