Corrosion Properties of Mn-Based Alloys Obtained by Aluminothermic Reduction of Deep-Sea Nodules

Materials

Pavel Novák¹  Alisa Tsepeleva¹  Pauline Miossec¹  Jaroslav Fojt¹  Šárka Msallamová¹  Jaromír Kopeček²  Darya Rudomilova³ 

[1] Department of Metals and Corrosion Engineering, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic;FZU-Institute of Physics of the Czech Academy of Sciences, Na Slovance 2, 182 00 Praha 8, Czech Republic;Technopark Kralupy, University of Chemistry and Technology, Prague, G. Karse 7/2, 278 01 Kralupy nad Vltavou, Czech Republic;

关键词: deep-sea nodules;    electrochemical measurement;    aluminothermic reduction;    Mn–Al alloy;    intergranular corrosion;   

DOI  :  10.3390/ma14185211

来源: DOAJ

【 摘 要 】

Deep-sea manganese nodules are polymetallic oxidic ores that can be found on a seabed. Aluminothermic reduction is one of the possibilities of manganese nodules processing. This process obtains the polymetallic alloy with a high content of Mn and a varying content of Al, depending on the ratio between aluminum and nodules. The corrosion behaviors of three experimental Mn-based alloys produced by aluminothermic reduction with a content of Mn > 50 wt % were studied. The electrochemical testing in potable water and model seawater was used to explain the corrosion mechanism of Mn-based alloys. The results showed that the corrosion rate of experimental Mn-based alloy decreases with the increase in aluminum content in both potable water and model seawater. It was observed that the uniform corrosion of experimental Mn-based alloys is changed with an increase in aluminum content in alloy to localized corrosion, which was caused by microcells in an environment of model seawater. In contrast, the formation of a semi-protective layer of corrosion products was observed on the surface of Mn-based alloys with a higher content of aluminum in potable water. Moreover, the pitting corrosion of tested Mn-based alloys was observed neither in potable water nor in model seawater.

【 授权许可】

Unknown