Abstract: The corrosion rates of the base metal zone，fusion zone and the heat affected zone of 2205DSS welded structures in various acid solutions are studied. It is found that the 2205DSS welded structure shows better corrosion resistance in oxalic acid and boiling nitric acid solution. However，the structure shows poor corrosion resistance in the hydrochloric acid solution obviously and the fastest rate of corrosion is the fusion zone，and the corrosion rate of base metal is followed. In the hydrochloric acid solution，the corrosion rate is accelerated as the temperature rises; the corrosion rate increases with the increase of hydrochloric acid solution concentration firstly and then decrease; the corrosion rate is reduced with the conduct of the etching time. The mathematical model of relationship among corrosion rate，temperature of the hydrochloric acid solution，concentration and etching time is established，which can quickly calculate the corrosion rate of the welded structures in the hydrochloric acid solution.

Key words: weld of 2205 duplex stainless steel, acid corrosion environment, corrosion rate

摘要： 试验研究了2205DSS 焊接结构的母材区、融合区、热影响区分别在草酸、硝酸和盐酸溶液中的腐蚀速率。研究发现:该结构在草酸和沸腾的硝酸溶液中有较好的耐腐蚀能力，而在盐酸溶液中较差; 熔合区腐蚀速率最快，母材区次之; 在盐酸溶液中腐蚀速率随着温度的升高而加快，随着盐酸溶液浓度的增加先增加后降低，随着腐蚀时间的进行而降低。建立了腐蚀速率与盐酸溶液的温度、浓度、腐蚀时间之间的数学模型，该模型能快速计算该焊接结构在盐酸溶液中的腐蚀速率。

关键词: 2205 双相不锈钢焊接处, 酸性腐蚀环境, 腐蚀速率