No abstract

Tuxpan is a port with economic and industrial important activity, has subject to the process of atmospheric corrosion of metal structures such as boats, ships, oil platforms and Thermoelectric. The main purpose of this paper is to evaluate the Atmospheric Corrosion of Tuxpan Veracruz, it was necessary to install a display panel with carbon steel specimens (Ac -R), galvanized steel (zinc ), aluminum and copper in order to evaluate them in every season by electrochemical methods (electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) and potentiodynamic polarization curves (CP) and at the end of the year by gravimetric techniques as established by CLIMAT and ISO methodology. The results show the aggressiveness of the marine atmosphere, mainly zinc and carbon steel due to aggressive agents such as chlorides and SiO 2 (silica). XRD analysis shows the presence of metal oxides formed on the metal substrate surface.

Faculty of Chemical Sciences in collaboration with the Institute of Engineering of the Universidad Veracruzana has developed a project for the construction of the Corrosivity Map of the State of Veracruz. Among the activities of the project is the evaluation of the indixes of atmospheric corrosivity in the city of Tuxpan Veracruz, due to the industrial, urban activities and to be located in a coastal area, characteristics that influence the corrosion of metallic materials exposed to the atmosphere. A exposition panel was installed with specimens of aluminum wire on steel screws, copper screws and plastic screws to study corrosivity indexes through mass loss in every season of year, and thus classify the different types of atmospheres; marine, industrial and rural-urban according to the values specified in the standard (ISO 8408, 9223, 9224). Corrosivity indexes obtained indicate a domain of rural-urban atmosphere product of excessive urban activities in the region. Expected to detect high levels of marine atmosphere by the presence of chlorides and particles resulting City location front of coast. However, corrosivity indexes for marine atmosphere are within the limit allowed by the normative.

The corrosive indexes were determined with Aluminum screwed wire probes over bolts of steel, cooper and plastic, also called CLIMAT (Classification of industrial and marine atmosphere) and accord with the technique reported by Bell Telephone Laboratories [1] and widely used by the company Aluminum Cable [2] for the study of galvanic unions of aluminum in the atmosphere conditions. Standard samples as carbon steel, galvanized steel, copper and aluminum were used to determine the categories corrosiveness type ISO in the city Poza Rica Veracruz. The Normative ISO 8565 was applied to the conditions of the exposure, and ISO 9223 for levels of corrosivity and calculating the corrosion rate of coupons after. This study was complemented with the application of electrochemical methods (EIS and CP), studies of morphology and surface analysis of corrosion products by scanning electron microscopy (SEM). The results indicate the existence of an industrial type atmosphere, influenced by the marine environment, from the Gulf of Mexico. According to the methodology CLIMAT was identified intermediate levels of atmospheric corrosion (C3) for carbon steel and (C4) for galvanized steel. However atmospheric corrosion was very high for copper (C5) and aluminum (C5). This can be attributed to the relative humidity above 80%, speed and wind direction, targeted attacks that produce aggressive agents such as SO2, chlorides, and suspended particles.

The corrosion of ASTM A-36 steel was studied in three electrolytes, NaCl, seawater, and NS4 solution, using the Linear Polarization Resistance and Electrochemical Impedance Spectroscopy technique for twenty days. At the same time, variations in the pH of the solution were recorded daily. To control corrosion of the steel an electronic prototype for an impressed current cathodic protection system (ICCPS) was developed in the laboratory taking into account current demand measurement. The prototype was developed with an Arduino UNO board and its modules. In the present work, the operation of the prototype controlling corrosion of A-36 steel immersed in NS4 solution is reported during 15 days of continuous exposure.