Print ISSN: 1681-6900

Online ISSN: 2412-0758

Current Issue
Volume 40 Issue 12 (Production and Metallurgy Engineering

Volume 40, Issue 12 (Production and Metallurgy Engineering, Material Engineering, 2 Articles), December 2022


Investigation Nano-coating for the Corrosion Protection of Petroleum storage tanks Steel

Zainab Z. Ali; Baha S. Mahdi; Ameen D. Thamer

Engineering and Technology Journal, 2022, Volume 40, Issue 12, Pages 1-9
DOI: 10.30684/etj.2022.131942.1074

This work studies the protection from corrosion in the inner surface of petroleum storage tanks by applying nano-coating on the AISI1018 steel type used in these tanks. BNi-2 alloy, used as coating layer, was deposited using the DC sputtering technique to obtain protection layers of nano-coating. The cyclic potential dynamic polarization technique is used to study and evaluate the resistant metal to localize corrosion, for example, pitting and crevice corrosion. The samples were evaluated in a 3.5% NaCl aqueous solution using the polarization method to determine the corrosion rate. The input parameters of deposition included ion current 16 mA, vacuum 10-1 mbar, time of deposition was 60 minutes, and the distance between target and substrate was 2.5 cm. The surface roughness of the uncoated specimens was (0.1466 µm), and after coating, it decreased to (0.0933µm). The most important factor that affects the corrosion of the coated steel surface is the surface topography of steel before coating, as it is known that the spattering process coats the facing surface to target better than the inclined surface topography. Therefore, some micro scratches non-coated well worked as nucleation for corrosion as detected in stereo microscope images for coated and uncoated surfaces. By calculating the corrosion rate from cyclic potential dynamic polarization for coated and uncoated workpieces, pitting and crevice corrosion improved approximately ten times compared to the uncoated AISI1018 steel surface.

Microstructure and Mechanical Properties of ZK60 Mg Alloy Processed by Cyclic Expansion-Extrusion (CEE) at Different Temperatures

Ahmed M. Marheb; Akeel D. Subhi

Engineering and Technology Journal, 2022, Volume 40, Issue 12, Pages 1-7
DOI: 10.30684/etj.2022.133572.1194

In this work, the cyclic expansion extrusion (CEE) process was applied to ZK60 Mg alloy. The correlation between the evolved microstructure and mechanical properties was investigated. The CEE process was performed at a constant ram speed (15 mm/min) and at different processing temperatures (190, 270, and 350 °C). Optical and scanning electron microscopes, X-ray diffraction instruments, Vickers hardness tester, and tensile testing machine were utilized to examine the influence of CEE processing temperature on the characteristics of ZK60 Mg alloy. The XRD analysis showed that two phases were presented in the matrix of ZK60 Mg alloy, namely α-Mg and MgZn2, in small amounts. The CEE process reduced the size of α-Mg grains due to dynamic recrystallization, especially at the processing temperature of 190 °C. A slight coarsening of the α-Mg grains was observed with increasing processing temperature to 270 and 350 °C. The hardness value ​​of ZK60 Mg alloy was enhanced by about 11 to 19% using the CEE process compared to the as-extruded sample. The processing temperature greatly affected the mechanical properties, where a significant improvement of about 24% yield strength, 9% ultimate tensile strength, and 38% elongation was observed using a processing temperature of 190 °C. The characterization of the tensile fracture surface of the tested samples indicated that the ductile-brittle fracture mode was responsible for the failure.

Characterization of the Efficiency of Photo-Catalytic Ultrafiltation PES Membrane Modified with Tungsten Oxide in the Removal of Tinzaparin Sodium

Reham R. Abdullah; Kadhum M. Shabeeb1; Aseel B. Alzubaydi; Alberto Figoli; Alessandra Criscuoli; Enrico Drioli; Qusay F. Alsalhy

Engineering and Technology Journal, 2022, Volume 40, Issue 12, Pages 1-10
DOI: 10.30684/etj.2022.134070.1219

One of the polymeric membranes' main limitations is their susceptibility to fouling, lowering the membrane's performance with time. Therefore, incorporating nanomaterials in polymer matrices has attracted great attention in wastewater treatment applications. It's a promising approach for enhancing membrane hydrophilicity and performance.  Herein, ultrafiltration nanocomposite membranes were synthesized by applying the phase inversion method through immobilizing (0.1-0.4 wt.%) tungsten oxide (WO2.89) nanoparticles in a polyether sulfone (PES) matrix. Membrane's anti-fouling performance was evaluated against tinzaparin sodium. The data showed that the pure water flux improved with increasing nanoparticle loading, reaching its optimum value of 54.9 kg/m2 h at 0.4 wt.% WO2.89 nanoparticles compared to the neat membrane's 30.42 kg/m2 h. The results also demonstrated that the rejection efficiency and flux recovery ratio (FRR) against tinzaparin sodium was enhanced, by 44.89% and 12.69%, respectively, for the membranes modified with 0.4wt.% WO2.89 nanoparticles loading compared to the neat PES membrane. The data also showed that after exposing the nanocomposite membranes to UV light irradiation (λ=365 nm) and intensity (1200mW/cm2) for 1h, a further enhancement by 8.34% in FRR as compared to the membranes with the same percentage of nanoparticles loading without irradiation. It is concluded that the photocatalytic activity of WO2.89 nanoparticles in the decomposition of organic molecules on/close to the membrane surface was the impact that caused this improvement in membrane anti-fouling property