Scale and Corrosion Inhibition of Three Water Stabilizers Used in Stainless Steel Condensers

• Published in: Corrosion (Houston, Tex.) Tex.), 2008-06, Vol.64 (6), p.553-557
• Main Authors: GE, H.-H, GUO, R.-F, GUO, Y.-S, ZHANG, H.-X, ZHOU, G.-D
• Format: Article
• Language: English
• Subjects: Applied sciences; Calcium; Calcium ions; Condensers; Condensers (liquefiers); Cooling; Cooling water; Corrosion; Corrosion environments; Corrosion inhibitors; Corrosion potential; Corrosion prevention; Cycles; Electric power generation; Exact sciences and technology; Metals. Metallurgy; Pitting (corrosion); Pitting potential; Power plants; Quality assurance; Raw water; Scale (corrosion); Stabilizers; Stainless steel; Stainless steels; Water quality
• ISSN: 0010-9312; 1938-159X
• DOI: 10.5006/1.3278491

Based on the requirement of a certain power plant, scale and corrosion inhibition of three water stabilizers used in Type 304 (UNS S30400) stainless steel condensers were studied. The cooling water used in this paper was the raw water that was actually used in this power plant. The polarization curves showed that the pitting corrosion did not occur on the stainless steel in the raw water, while pitting might occur when the raw water was concentrated. The higher the cycles of concentration, the lower the pitting potential was. The results of water quality analysis indicated that the ratio of [Cl−]/[Ca2+] increased during the concentrating process. The experimental results of the three water stabilizers, named as no. 1, no. 2, and no. 3, respectively, showed that pitting might not take place when the cycles of concentration were less than or equal to 3 in the cooling water containing the no. 1 stabilizer, and the water quality analysis indicated that the ratio of [Cl−]/[Ca2+] was unchanged. The ratio of [Cl−]/[Ca2+] increased with the concentration going on, and the pitting potential decreased rapidly at the same time. The pitting might not take place when the cycles of concentration were less than or equal to 5 in the cooling water containing the no. 2 stabilizer; while the pitting still might not occur until the cycles of concentration reach 6 in the cooling water containing the no. 3 stabilizer, which indicated that the no. 3 stabilizer was the best one on scale and corrosion inhibition.