Influence of Temperature on the Protectiveness and Morphological Characteristics of Calcareous Deposits Polarized by Galvanostatic Mode

• Published in: Acta metallurgica sinica : English letters 2014-02, Vol.27 (1), p.131-139
• Main Authors: Li, Chengjie, Du, Min, Qiu, Jing, Zhang, Jing, Gao, Congjie
• Format: Article
• Language: English
• Subjects: Aragonite; Calcite; Calcium carbonate; Cathodic protection; Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion; Corrosion and Coatings; Critical temperature; Deposits; Electrodes; Electrolytes; Investigations; Linear polarization; Materials Science; Metallic Materials; Nanotechnology; Nyquist plots; Nyquist图; Organometallic Chemistry; Seawater; Spectroscopy/Spectrometry; Temperature; Tribology; X-射线衍射分析; 保护性; 形态特征; 沉积; 温度; 电流模式; 钙质
• ISSN: 1006-7191; 2194-1289
• DOI: 10.1007/s40195-013-0010-6

The influence of temperature on calcareous deposits formed under galvanostatic polarization mode was studied. The deposition was monitored by electrochemical impedance spectrum, and a supplementary loop in Nyquist diagram at high frequency was found to be an indicator of deposits precipitation with sufficient protection at above 20 ~C. An exponential increase of protectiveness with temperature was observed, which was quantified by linear polarization resistance technique. Observation by scanning electron microscope and X-ray diffraction analyses demonstrated that the critical temperature of calcium carbonate crystal form transition ranged from 15 to 20 ℃. Calcite formed below 15 ℃, while aragonite precipitated at above 20 ℃.