Characterization of Working Thicknesses of Some Bath-Dip-Produced Corrosion – Protective Bitumen Coatings on Polish-Prepared Low Carbon Steel Specimens
The coating thickness is an important variable that plays a role in product quality, process control and cost. Determination of the required working thicknesses for different service requirements is however a complicated task in the product finishing field. A previous study has shown that Nigeria is blessed with abundant bitumen resources for sustained exploitation as common, economical and effective coat-inhibitors of steelwork corrosion in her economy. This paper presents a testdetermination of the expected range of working thicknesses of coatings with proper bitumens from the resources. Bitumen samples were harvested at three different critical bitumen resource sites in the country for the tests. 30 specimens of the steel were properly prepared. Coatings of different thicknesses were produced on the specimens by dipping a different pair of them in each bitumen sample heated to each of five different temperatures in the range of 170 – 230 O C and removing and cooling them to 38 O C-room-temperature. The thickness of each produced coating was properly determined with a micrometer through dimensional change before and after coating. Analysis of the overall obtained data shows that the average working thicknesses of coatings with any bitumens of comparable quality to the as-harvested from the resources using temperatures in the range will decrease with increase in temperature from about 1.46 to 0.81mm respectively, and thicknesses of coatings with the separate bitumens using the same bath temperature will have minimal variations.
Marine Corrosion
This brief discussion will highlight the types of marine corrosion problems that are encountered in Naval service. Literally millions of parts are involved in the construction and use of Naval ships and all may be subject to the deleterious effects of seawater unless suitable precautions are taken. The important aspect of marine corrosion is to be aware of the limitations of materials and to understand the material/environment interactions in order to overcome such limitations.
Standardization of NIRR-1 irradiation and counting facilities for instrumental neutron activation analysis.
The first nuclear reactor in Nigeria, the Nigeria Research Reactor-1 (NIRR-1), is a Miniature Neutron Source Reactor (MNSR). It was specifically acquired for elemental analysis by the neutron activation analysis (NAA) technique. In this work, routine experimental schemes for the determination of over 30 elements of interest in different sample matrices have been developed. In order to validate the experimental procedures the following standard reference materials, IAEA-359 (Cabbage), IAEA-336 (Lichen), GSR-5 and GSD-11 (Chinese Geochemical Rock Standards), as well as IAEA-SL-3 and IAEA-405 (Sediments) were analyzed. Validated results are presented for the following elements Al, As, Au, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Cu, Dy, Eu, Fe, Ga, Hf, In, K, La, Lu, Mg, Mn, Na, Rb, Sb, Sc, Sm, Ta, Tb, Th, Ti, U, V, Yb and Zn. To further assess analytical capabilities of the facilities, the detection limits are presented.