含铜双相不锈钢在无菌/含菌环境下的耐蚀性研究

Corrosion Resistance of Copper-bearing Duplex Stainless Steel in Culture Medium without and with Bacteria

对经固溶处理的含铜双相不锈钢材料进行了540,560和580℃时效处理。利用电化学工作站研究了固溶及时效处理试样在无菌/含菌培养基中的耐蚀性,同时采用OM及XPS检测手段对固溶处理试样及抗菌性最优的经560℃时效处理试样菌液腐蚀后的生物膜形貌及表层Cu的腐蚀产物进行了分析。结果表明,在无菌培养基中,固溶处理试样最耐蚀,经时效处理的试样随时效处理温度的升高,耐蚀性下降;在含菌培养基中,经560和580℃时效处理试样的耐蚀性比其在无菌环境中的有所提高,固溶处理及经540℃时效处理试样的耐蚀性比其在无菌环境中的有所下降。固溶处理试样表面存在厚大疏松状生物膜,表层腐蚀产物中Cu CO3含量相对较低,细菌腐蚀导致试样在含菌介质中的耐蚀性比其在无菌介质中的差;经560℃时效处理试样的表层覆盖稀薄生物膜,细菌对试样腐蚀破坏作用弱,表层腐蚀产物中Cu CO3含量高,Cu CO3对试样的保护作用大于细菌的破坏作用,使得其在菌液中的耐蚀性比其在无菌环境中的有所提高。

Effects of aging treatment at 540~580 ℃ on the corrosion resistance of a copper-bearing duplex stainless were studied by electrochemical measurement in culture medium with and without bacteria. The surface morphology of the biofilms and the corrosion products formed on the steels solution treated and aging treated at 560 ℃ were characterized by OM and XPS. The results show that in the culture medium without bacteria, but the proportion of coarse copper- rich phase in the corrosion products on the aged steel increases with the increasing aging temperature, correspondingly the corrosion resistance of the aged steels became worse; in comparison with those in the culture medium without bacteria, the corrosion resistance of the steels solution treated and aged at540 ℃ is inferior, while of the steels aged at 560 and 580 ℃ is better in the culture medium with bacteria, correspondingly a thicker porous microbiological biofilm with low Cu CO3 content formed on the steel solution treated in the culture medium with bacteria, which possessed less protectiveness, while a thin and dense biofilm with high Cu CO3 content formed on the steel aged at 560 ℃,which could enhance the corrosion resistance of the steel.