Calcareous Deposits and Effects on Steels Surfaces in Seawater – A Review and Experimental Study

Abstract

This article reports the various research investigations by many scientists on seawater composition, particularly, on calcareous deposits and effects on mild and austenitic stainless steels in seawater and relative to their protection against corrosion. The main areas of attention include the factors and the mechanisms that influence the formation of calcareous deposits; solubility of calcite and aragonite, calcareous deposition and the growth kinetics effects of temperature and magnesium. Also reviewed are the solution behaviour of carbonate materials and the factors that influence calcium carbonate precipitation. A review of an extensive field and laboratory investigation on the performance evaluation of super austenitic stainless steels in seawater was also reported. Field tests and laboratory examinations were used to determine Field tests and laboratory examinations were used to determine the corrosion susceptibility of selected super austenitic stainless steels in seawater. The tube(s) surface biofilm enrichment at the different areas of the tube was confirmed with EDAX spectroscopic analysis as consisting of chemical elements such as Ca, Mg, Cl, P and Si. Analysis with X-ray diffraction confirms more enrichment of biofilm in the steam chamber with Fe, Ca, and Mg than the outlet tube biofilm. The presence of CaCO3 – calcite and aragonite was confirmed as the major composition of the calcareous layer deposited on the metal’s surface.