Application of Response Surface Methodology for Modelling and Optimization of Hot Corrosion Rate of Nimonic 75 Coated by Ce-doped Aluminizing-Titanizing

Response surface methodology (RSM) was used to determine the optimum conditions (wt.% of Na2SO4, %wt. of V2O5, and Temperature ) that give the minimum hot corrosion rate (Kp) (g2 cm-4 s-1) for Nimonic75 coated by Ce-doped Aluminizing- titanizing . Experiments were designed according to central composite design in response surface methodology with these three factors using MINITAB 16 and MATLAB 2014a Software. The variation of hot corrosion rate (Kp) with hot corrosion parameters was mathematically modeled using response surface methodology. The optimum conditions obtained were 40 wt.% of Na2SO4, 40 %wt. of V2O5, and 900oC . This resulted in ( Kp=1.430987×10-10 g2 cm-4 s-1 ) as obtained from the predicted model , which fitted well with the laboratory verification result ( Kp=1.4311×10-10 g2 cm-4 s-1 ) . This was supported by the high value of coefficient of determination (R2=99.81%) of the Predicted model . The high correlation coefficient (R2= 98.991%) between the model and the experimental data show that the model was able to predict the hot corrosion rate from hot corrosion conditions

Computer Simulation Using Fuzzy LogicModel to Predict Hot Corrosion Kinetics in Molten Salt of Steel-T21 Coated by Simultaneous Yttrium-Doped Aluminizing-Siliconizing Process

The present paper describes fuzzy logic simulation of an experimental study on the behavior of hot corrosion in molten salt (Na2SO4) of steel-T21 coated by simultaneous yttrium-doped aluminizing-siliconizingprocess . Diffusion coating was carried out at 1050oC for 6 hr under Aratmosphere . The weight change measurements made on the coated steel during the cyclic tests are used to determine kinetics of hot corrosion at temperature range (800-1000oC) for 100 hr at 5 hrcycle .X-ray diffraction and optical microscope are used to characterize the oxide phases where the oxide phases that formed on coated system are SiO2 and Al2O3 .The parabolic rate constants (Kp) calculated show that the corrosion rate is minimum at 800oC compared to other temperatures. The experimental results, the fuzzy logic model, and the statistical results showed good correlations.The fuzzy logicmodels are developed using Matlab toolbox functions

INVESTIGATION CORROSION AND MECHANICAL PROPERTIES OF CARBURIZED LOW CARBON STEEL

In this research, Taguchi method is used (S/N) ratio for measuring the variations in experimental design. Taguchi designs used in converting the multi-performance problem into a single-performance problem for experiments which will are in building (Taguchi (L27) orthogonal array) for carburization operation. The main variables that had a great effect on carburizing operation are Carburization temperature (o C), carburization time (hrs.) and tempering temperature (oC). It was focused also on calculating the amount of carbon penetration, the value of hardness, wear rate, corrosion rates and optimal values obtained during the optimization by (Taguchi) approach method for multiple parameters. In this study, the carburization process was done in temperature between (850 to 950 ᵒC) for (2 to 6 hrs.). Quenching process was done for the specimens after heat treatments in furnace chamber by different quench solution (water, salt and polyvinyl alcohol). Taguchi design used to achieve maximum hardness and depth penetration, Minimum wear and corrosion rates

Effect of Filler Type on some Physical and Mechanical Proparties of Carbon Fibers / Polyester Composites

In the present study, traditional and hybrid composites were prepared by Hand lay-up molding and investigated. The composites constituents were unsaturated polyester resin as the matrix, 3% and 6% volume fractions of carbon fibers as reinforcement and 3% of Al2O3, Al, Cement and local Gypsum (calcium sulfate anhydrate CaSO4) as filler particles. The investigated physical properties were density, porosity while the mechanical properties were tensile properties, bending modulus of elasticity. The experimental results showed that increased volume fraction of carbon fibers to (6%) led to increase in physical properties (density, porosity. As for the mechanical properties, carbon fiber composites and (3% carbon fibers/Al2O3)-contained hybrid composites gave the higher tensile and fracture strength, carbon fiber then gypsum composites gave the higher bending modulus

Ciliotherapy: A Novel Intervention in Polycystic Kidney Disease

Background Ciliopathies are a group of diseases associated with abnormal structure or function of primary cilia. Ciliopathies include polycystic kidney disease (PKD), a pathology associated with vascular hypertension. We previously showed that cilia length regulates cilia function, and cilia function is required for nitric oxide (NO) biosynthesis in endothelial cells. Because patients with PKD show abnormal sensory cilia function, the aim of our current study was to search for a targeted therapy focused on primary cilia, which we refer to as ‘cilio-therapy’. Methods and Results In the present studies, our in vitro analyses refined fenoldopam as an equipotent and more specific dopa- minergic agonist to regulate cilia length and function

Optimization of Wear Parameters in AISI 4340 Steel

This study investigated the optimization of wear behavior of AISI 4340 steel based on the Taguchi method under various testing conditions. In this paper, a neural network and the Taguchi design method have been implemented for minimizing the wear rate in 4340 steel. A back-propagation neural network (BPNN) was developed to predict the wear rate. In the development of a predictive model, wear parameters like sliding speed, applying load and sliding distance were considered as the input model variables of the AISI 4340 steel. An analysis of variance (ANOVA) was used to determine the significant parameter affecting the wear rate. Finally, the Taguchi approach was applied to determine the optimum levels of wear parameters. The results show that using the optimal parameter setting (load3, sliding speed1, and sliding distance2) a lower wear rate is achieved. The error between the predicted and experimental values is only 3.19%, so good agreement between the actual and predicted results is observed

Improved acrylonitrile-butadiene-styrene surface properties via electroless (NiP-SiC) nanocomposite coating

By using electroless nickel-phosphor plating techniques, several (NiP-SiC) nanocomposite coatings were applied to acrylonitrile-butadiene-styrene (ABS) substrates at different temperatures and deposition times. Field emission scanning electron microscope (FESEM) images show that different coating morphologies have been produced. The energy-dispersive x-ray spectroscopy (EDX) data demonstrate that the (NPs) were successfully integrated and nickel and phosphorus are the principal components of the coating. The nickel peaks have been noticed at an angle around (43.29⁰) which belongs to Ni (111) using an X-ray diffraction analysis (XRD) pattern for (NiP-SiC NCCs) produced under different immersion times and temperatures. The nanocomposite coating that was made at 95 °C for 30 min showed the best hydrophobic properties, with a maximum contact angle value of (119.68°), according to the contact angle data. The corrosion behavior was studied via the electrochemical method in (3.5 wt.%) NaCl at (25 °C), and the results showed that the best polarization resistance for the (NiP-SiC) coating is obtained at (90 min at 75 °C) deposition conditions and is (45.14222 kΩ. cm) which produce complete coverage compact coating with growth globular. The best hardness value recorded for a coating that has the most nucleation sites came from a high incorporation nanoparticles level with a small nodule structure which formed at (30 min and 75 °C) and is (3.15 GPa). Finally, the lower wear rate value was collected for the coating having the lower coefficient of friction which was produced at (30 min at 75 °C) deposition conditions and is (0.023 mg/m))