2205双相不锈钢硫酸露点腐蚀性能的研究

利用实验室模拟硫酸露点腐蚀的试验方法对2205双相不锈钢的腐蚀行为进行研究,并与传统不锈钢316L和304进行对比。结果表明,腐蚀失重的方法对3种材质的腐蚀速率由快到慢排序为:304316L?2205,且2205双相钢的腐蚀深度为0.001 08mm/a,接近完全耐蚀材料等级。结合SEM、电化学工作站对3种试件的腐蚀形貌、电化学性能进行分析。2205双向钢的腐蚀表面无点蚀坑,仅存在很少的贫Cr区,同时2205双相钢的自腐蚀电流为0.574 6A/cm~2,明显低于316L和304不锈钢,自腐蚀电位为-68.4mV,较316L和304不锈钢高出了近300mV,同时2205双相钢的电荷转移电阻为2.2×10~4Ω/cm~2,约是316L的42倍,是304不锈钢的473倍。因此,3种材质中2205双向钢可以作为耐硫酸露点腐蚀的首选用钢。

Research on the Dew Point Corrosion Performance of 2205 Duplex Stainless Steel in Sulfuric Acid

Using laboratory simulation of sulfuric acid dew point corrosion test method to study the corrosion behavior of 2205 duplex stainless steel ,and comparing the results with traditional stainless steel 316 L and 304 ,it is found out that with corrosion weightless method ,the corrosion rate of three kinds of materials is 304>316 L>>2205 (from fast to slow ) ,and the 2205 duples steel corrosion depth is 0.001 08 mm/a ,close to corrosion resistant materials .Combined with SEM ,the electrochemical workstation analyzed the three types of corrosion morphology and the electrochemical properties of the specimens ,which showed that there were no corrosion pits on the surface of 2205 duples steel .There only existed a few poor Cr areas .The corrosion current of 2205 duples steel was 0.574 6 A/cm2 ,significantly lower than 316 L and 304 stainless steel .The corrosion potential was 68.4 mV ,which was nearly 300 mV higher than that of stainless steel 316 L and 304 .The charge transfer resistance of 2205 duples steel was 2.2 × 104 Ω/cm2 ,about 42 times higher than 316 L ,about 473 times higher than 304 stainless steel .Therefore ,2205 duples steel can be used as the first choice for sulfuric acid dew point corrosion resistant steel among the three kinds of material .