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Abstract:The ability to detect and classify damages in complex materials and structures is an important problem from both safety and economical perspectives. This paper develops a novel approach based on geostatistical analysis for the corrosion prediction. Our approach is based on using geostatistics for modeling oil tank thickness from nondestructive data. First of all the semivariogram was obtained from the scatter points set. Then computing the ordinary kriging predictions at unmonitored points. Finally, simulating the thickness along the surface of the tank.

Polymer nanocomposites consist of a polymeric substances and a nanoscale reinforcing materials. These materials show substantial improvements in mechanical properties, gas barrier properties, thermal stability, chemical resistance, dimensional stability and fire retardancy over the base polymer. The reinforcing effect of nano-clay on high density polyethylene (HDPE) and the effect of gamma radiation on the properties of HDPE with different ratios of nano-clay have been studied. The nano-clay are added to HDPE of 0%, 3.0%, 5.0%, 7.0% and 10.0% by weight. After the nano composites are exposed to different doses of gamma radiation, the phase composition microstructure and mechanical properties of composites are investigated using tensile test, hardness and scanning electron microscope (SEM) techniques. Results show that the mechanical properties of nano-composites are improved due to addition of nano-clay. It is found that the optimum 3 wt % nano-clay addition. The microstructural analysis results indicate that the nano-clay behaves not only as a filler to improve the microstructure, but also as an activator to facilitate the polymer reaction. The mechanical properties were investigated as a function of irradiation dose and nano-clay content. Gamma irradiation led to a significant improvement in the properties for all composites up to 100 KGy.

Clading metal weld is a composite product developed to provide effective and economic utilization of expensive materials. The welding layer NiCu and NiFe that will be in contact with the corrosive media is made of the corrosion resistant alloys, whilst the less expensive base carbon steel covers the strength and toughness required to maintain the mechanical integrity. In a nuclear power plant clading metal weld joints are necessary for joining the different materials chosen for the various parts of the heat transfer circuit. Also Clading metal welds are utilized in processing pressure vessels, heat exchangers, tanks and storage facilities. Anodic polarization curves for deposited as weld and heat treated Ni alloy weld metal in 3.5% NaCl solution with alkaline pH are studying. Anodic polarization curve for NiFe weld metal on carbon steel heat treated for 50,500 and 1000 hr at 550 oC are recorded. The results indicated that, for example, the anodic polarization curve for NiFe weld metal heat treated for 500 hr at 550 oC in 3.5% NaCl solution, the corrosion current density was 11.23 μ A/cm 2 .The corrosion current density increase at constant rate which indicate a uniform corrosion. The hardness is 205Hv measured at 300 gmload.As for the anodic polarization curve for Ni-Cu weld metal heat treated for 500 hr at 550 °C tested in 3.5% NaCl solution, the corrosion current density was 28.42 µA/cm 2. The corrosion current density increases after that with constant rate till and of the experiment. The hardness is 235Hv measured at 300 gm load.

Dissimilar metal welding is frequently used to join carbon steels to other materials such as nickel metal. This approach is most often used where a transition in mechanical properties and/or performance in service are required. The power generation industry uses dissimilar metal welding extensively to reduce material costs and enhance performance in elevatedtemperature applications.Anodic polarization curves for deposited as weldcondition of Ni weld metal on carbon steel in 3.5% NaCl solution having neutral pH are studying. Anodic polarization curve for thermal aging of Ni weld metal for different agingtimes50,500 and 1000 hr at 550ºCare also recorded. The results indicated that the corrosion current of the Ni weld metal on carbon steel increases as aging time increase,also the grain size of the deposited Nickel increase during thermal aging for different times 50, 500 and 1000 hours respectively