船用结构钢合金成分优化及耐微生物腐蚀性能研究

为了优化船用结构钢合金元素,提高其耐微生物腐蚀性能,研究了船舶用结构钢冶炼中常见的10种重金属元素对海洋微生物生长的抑制能力,探讨了金属离子毒性与细菌胞外分泌物(EPS)选择吸附的关系,并采用电化学、倒置荧光显微镜和原子力显微镜分析了经过合金元素优化后的试样的耐微生物腐蚀性能。实验结果表明,金属离子抑制毒性与 EPS 的选择吸附有密切关系,EPS 对这些金属离子的吸附能力越强,该金属离子对细菌的毒性就越大；对于革兰氏阴性菌而言,各重金属离子的毒性大小为 Cu2+> Zn2+>Ni2+>Pb2+>Cr3+>V5+>Co2+>Mo6+>Mn2+> Al3+,对于革兰氏阳性菌而言,各重金属离子的毒性大小为 Ni2+> Zn2+> Cu2+> Co2+> Cr3+>Pb2+>V5+> Mn2+> Mo6+> Al3+；优化 Ni、Cu、Cr 三种合金元素在试样中的含量,在一定程度上均可以加强试样在无菌介质和有菌介质中的耐腐蚀性能。同时提高合金元素 Ni、Cu 和 Cr 在钢材中的含量对于提高材料的耐微生物附着腐蚀性能最为显著。

Research on the Optimization of Alloy Content and Corrosion Resistance of Marine Structure Steel

In order to optimize alloying elements of marine structural steel and improve the microbial corrosion resistance performance, the effect of 10 kinds of heavy metals on the growth of marine microbial, and the relationship between the ability of selective adsorption of bacterial extracellular secretion (EPS) and the toxicity of metal ion were discussed, and corrosion performance of the optimized metal coupons was studied by electrochemical,inverted fluorescence microscope and atomic force microscopy(AFM). The experimental results showed that the stronger the adsorption ability of EPS, the greater the toxicity of the metal ions on bacteria, the order of toxicity as followed:Cu²⁺>Zn²⁺>Ni²⁺>Pb²⁺>Cr³⁺>V⁵⁺>Co²⁺>Mo⁶⁺>Mn²⁺>Al³⁺ for Gram negative bacteria, and Ni²⁺>Zn²⁺>Cu²⁺>Co²⁺>Cr³⁺>Pb²⁺>V⁵⁺>Mn²⁺>Mo⁶⁺>Al³⁺ for Gram-positive bacteria. Respectively increasing the Ni, Cu and Cr content in the steel could partly enhance the corrosion resistance of the coupons to culture with and without bacteria. Moreover, the effect of the inhibitor microbiology corrosion of the coupon with addition of Ni, Cu and Cr content at the same time was most significant.