Corrosion studies sites

The Corrosion Doctors site at http //www.corrosion-doctors.org contains lots of interesting case studies. 

The unique setting of the Werra-Fulda district allows not only the study of basalt alteration, but also the ability to trace basalt-derived elements within the salt. The study site is thus, on one hand, a natural analogue for the long-term corrosion expected for nuclear waste glass in... 

Atmospheric corrosion studies were performed in the Spanish Canary Islands exposing zinc, copper, and carbon steel sheets to the subtropical and coastal environment for a period of 3 years [45-47]. The first part of this study was to determine the corrosion rates on each sample at different times. The study also performed an analysis of the atmospheric conditions at the thirty-five test sites on the islands. With this information, the atmospheres were classified according to ISO. Measured corrosion rates were compared with the expected ISO values. The corrosion rates obtained based on ISO were determined deficient throughout the studied region... 

A few simulative studies addressing the processes occurring on the steel surface that cause atmospheric corrosion at sites have been carried out and mechanism of rusting process of WS and MS has been proposed. The aim is to develop an early formation of protective rust on WS by applying various surface treatments using electrolytes and suggesting ways to improve the weathering characteristics. 

A four year atmospheric corrosion study was conducted for carbon steel and galvanized steel at five different sites around Kuwait. In August 1991, an atmospheric corrosion study was initiated for the state of Kuwait for duration of four years. This study was particularly important for Kuwait and the Gulf region at that time because of the burning oil well... 

Three factors influence the rate of corrosion of metals—moisture, type of pollutant, and temperature. A study by Hudson (1) confirms these three factors. Steel samples were exposed for 1 year at 20 locations throughout the world. Samples at dry or cold locations had the lowest rate of corrosion, samples in the tropics and marine environments were intermediate, and samples in polluted industrial locations had the highest rate of corrosion. Corrosion values at an industrial site in England were 100 times higher than those found in an arid African location. 

This is primarily engaged in analysis of boiler water treatment matters and involves on-site studies of various problems and the chemical examination of corrosion products, boiler scales, etc. It can also carry out certain types of metallurgical, fuel and inorganic analysis. Normal wet methods of analysis coupled with a visible ultraviolet and atomic absorption spectrophotometer are used for a wide range of analytical applications. Equipment in use by the engineering insurers providing these services can include an ion chromatograph, spectrometer equipment, atomic... 

It should be noted that it is extremely difficult to predict service lives of buried pipelines from the results of controlled trials with small specimens, whether in the laboratory or in the field. For example a study on the comparative corrosion resistances of ductile and grey iron pipes carried out jointly by European pipemakers in 1964-1973 indicated a mean pitting rate of 0 -35 mm/y for uncoated ductile iron pipe exposed in a typical heavy Essex clay of 500-900 ohm cm resistivity for 9 years. This is clearly at odds with the rate of 1 mm/y normally found on a corroded service pipe from such a soil. The discrepancy appears to be due to the use of specimens that were only a third of a pipe length each and were buried separately. It may reflect the contribution of the total surface area of the pipe as a cathode to the corrosion current at the anodic area at the pitting site. 

Corrosion of. power-station condenser tubes by polluted, waters has been particularly troubles ome in Japan anil efforts have been made to,study the problem by, electrochemical methods and by exposing model condensers at a variety of bower station sites ., Improved results have been reported, using tin. brasses , or special, tin bronzes. . Pretreatment with sodium dimethyldithiOcarbamate is reported to give protective films that will withstand the action of polluted waters , though the method would be economic only in special circurtistapcies., , , . ... 

Specifics on the types and rates of microbiological attack. These must be determined by using other methods such as chemical and microbiological analysis of the solution and materials from the corrosion sites. Consideration must be given to limitations of electrochemical techniques for MIC studies, noted previously under Corrosion Testing Laboratory Tests and subsequent subsections. 

Carbides have been studied for ORR in acidic media.219,220 Tungsten carbide was shown to be promising for ORR in acidic media,219 though WC has a corrosion problem in acidic systems.221 To increase the stability of the catalyst in PEM fuel cell conditions, tantalum was added to tungsten carbide.220 The Ta-WC catalyst was tested under fuel cell conditions and compared to WC. The corrosion resistance was markedly improved as well as the activity for ORR. It is thought that a Ta-W alloy acted as a stabilizer for the catalyst while WC remained the active site for ORR.220... 

The most conventional investigations on the adsorption of both modifier and substrate looked for the effect of pH on the amount of adsorbed tartrate and MAA [200], The combined use of different techniques such as IR, UV, x-ray photoelectron spectroscopy (XPS), electron microscopy (EM), and electron diffraction allowed an in-depth study of adsorbed tartrate in the case of Ni catalysts [101], Using these techniques, the general consensus was that under optimized conditions a corrosive modification of the nickel surface occurs and that the tartrate molecule is chemically bonded to Ni via the two carbonyl groups. There were two suggestions as to the exact nature of the modified catalyst Sachtler [195] proposed adsorbed nickel tartrate as chiral active site, whereas Japanese [101] and Russian [201] groups preferred a direct adsorption of the tartrate on modified sites of the Ni surface. 

---