Effects of Sodium Nitrite, Sodium Dichromate and Benzoic Acid as Inhibitors in the Protection of Mild Steel in Water

Abstract:

In Petrobrás SA refineries, there are thousands of heat exchangers in which cooling water is treated for recycling, often by outsourced companies. In all of these refineries there happens shutdown for corrective maintenance of the exchangers by problems related to corrosion caused by the cooling water, requiring about four days to repair a unit. The shutdown of a production line results in loss of revenue between U$ 200,000.00 and U$ 300,000.00 per day. To control the cooling water quality, it is used coupons for corrosion analysis. Tests are limited to visual inspection and by mass loss analysis. In this work, inhibitors such as sodium nitrite, sodium dichromate and benzoic acid are used to protect metals immersed in water in order to avoid the corrosion and consequently the shutdown of the exchanger for corrective maintenance.

• Periodical: Materials Science Forum (Volume 802)
• Pages: 433-439
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.802.433
• Online since: December 2014
• Authors: José Wilson de Jesus Silva*, A.P.O. Belo, R.B. Ribeiro, N.T. Matias
• Keywords: Corrosion Resistance, Coupons, Inhibitors, Steel

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