الفهرس | Only 14 pages are availabe for public view |
Abstract It is well know that recirculating open cooling water system at metal/ water surface contact appear frequent corrosion products, like scales, foaling and material losses which are have great effect on cooling process. Passivation helps to maintain clean heat transfer surface by inhibiting oxides scales through creating outer passive layer. The study of passivation of carbon steel pipe line in recirculating open cooling water system was the aim of this present work. Maximum efficiency of passivator was determined and surface morphology were investigated using optical, scanning microscopy, phase analysis of the formed protective layer was exam by X - Ray Diffraction (XRD) and Energy-Dispersive X-Ray Spectroscopy (EDX). Corrosion in running water with and without PSO at 2 m3/hr flow rate was investigated using corrosion coupon rack. It was foun`d that 200 ppm (PSO) decreases corrosion rate of carbon steel pipe in 3.5% NaCl solution from 23 to 7 mpy in stagnate water corrosion testing, while in running water in 3.5% NaCl solution it decreases from 45 to 18 mpy. XDR showed that the protective layer due to passivation is mainly Magnetite (Fe3O4) compound. |