Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : corrosion

Study the Effect of Erosion-Corrosion of Al-Mg-Si Alloy in Marine Environment

Nawale E. Abdal-Latefe; Mohammed Abdulateef Ahmed; Sondus Mohamed

Engineering and Technology Journal, 2013, Volume 31, Issue Issue 2 A, Pages 245-264

Erosion–corrosion of Al-Mg-Si aluminum alloy in NaCl–water solutions were studied by weight-loss measurements through an impingement jet system. The effect of sand concentration and fluid impingement angle, were investigated. The sand used is Iraqi silica sand from Al-ardhimah .
The result showed that, increasing erosion time, will increase the erosion rate of alloy samples for all sand concentration and impact angels. When the sand concentration is increased the erosion-corrosion rate of alloy samples will increase, and the maximum value of erosion –corrosion rates occur when the impact angle is about( 45◦).The surface morphologies of eroded surface after abrasive water-jetting, show that erosion rather than corrosion, controls the total Erosion-Corrosion rate of Al-Mg-Si alloy in sand-containing NaCl–water solutions.

Finding the Weight Loss Rate of Metallic Surfaces Exposed To Corrosion Presence of Vibration (Corrosion - Vibration)

Mouhmad Abdultef Ahmed

Engineering and Technology Journal, 2012, Volume 30, Issue 20, Pages 448-462

In this research the structural steel type (A36) samples were prepared by
traditional preparation operations , chemical composition of samples was analyzed
, hardness tested, then testing corrosion was achieved for two major cases, a
general corrosion case when the corrosive medium (sea water) is static for five
days period ,and the second case is the corrosion with presence of mechanical
vibration, which included two branch cases , first case; corrosion of vibrated
samples with the vibrated corrosive medium, and the second case when the
samples are fixed and corrosive medium is vibratory , a total test period is five
hours for each case ,then found weight loss and the corrosion rate of all cases of
corrosion mentioned by a traditional weight loss method , as well as study the
microstructures before and after the corrosion cases and to find an experimental
mathematical formula that illustrate the relationships between corrosion and
corrosion with presence of vibration, note that the used device to study the
mechanical vibration effect was locally designed and manufactured, according to
the modified American Standard (ASTM G32).Observed that the weight loss and
corrosion rate reached the highest value in the second case of corrosion with
presence of mechanical vibration (fixed samples and corrosive medium is
vibratory), followed by the first case of corrosion with presence of mechanical
vibration (vibrated samples with the vibrated corrosive medium), and less the value
of the corrosion rate and weight loss is the state of general corrosion (corrosion in
the static medium). It was noted that the microstructure of the structural steel
became uniformly corroded after general corrosion case (in static corrosive
medium) and corrosion regions were spread or scattered over all parts of the
sample surface on a regular basis, while the microstructure in the two cases of
corrosion with presence of mechanical vibration containing irregular corrosion
cavitations and scattered randomly on the surface, and more deeply especially the
second case (fixed samples and corrosive medium is vibratory). Illustrated from the
results and carves there was relationship between mentioned corrosion cases, it was
an experimental mathematical formula:
Acc.C.R.= Vib-C.R2 – ( Vib-C.R1 +Static C.R.)

Effect of Some Anti-Inflammatory Drugs on The Corrosion Behavior of Implant Biomaterials in Human Body Fluid

Kahtan K.Al-Khazraji; Ali H. Ataiwi; Rana A. Majed; Zina Noori Abdulhameed

Engineering and Technology Journal, 2012, Volume 30, Issue 6, Pages 959-973

The aim of this research is to compare the electrochemical behavior of two surgical implant biomaterials alloys, SS 316L and Co–Cr–Mo alloy in simulated body fluid. This comparison is focused on the influence of presence of three anti-inflammatory drugs, aspirin (C9H8O4), paracetamol (C8H9NO2), and mefenamic acid (C15H15NO2) with three
concentrations of each drug (0.00303, 0.00606, and 0.01212), (0.0086, 0.0172, and 0.0344), and (0.00111, 0.00156, and 0.00201) g/300ml respectively at pH=7.4 and 37oC using electrochemical techniques, potentiodynamic curves and potentiostatic tests. Influence of these drugs on both biomaterials depends on the formation of
organometallic complexes between released metals ions from implant alloys and drugs molecules. The study shows that the drugs behave as inhibitors for SS 316L through the measured corrosion parameters, while gives irregular behavior in the case of Co – Cr – Mo alloy. However, difference between two alloys appear with different affinity of
released metal ions to binding with other molecules inside human body.

Studying the Effect of Chemical Solution on Corrosion Behavior of SiC and Al2O3 Reinforced Aluminum Composite Materials

Nervana A. Abd Alameer

Engineering and Technology Journal, 2011, Volume 29, Issue 15, Pages 3194-3203

Corrosion behavior of aluminum matrix composites (MMCs) with (10, 20 &30) weight fraction of each alumina and silicon carbide was investigated in 10% (NaCl, NaOH &HCl) solutions at different temperatures (40, 60, 80 &100) °C also at room temperature. The results showed the corrosion rate was increased with increasing in
weight fraction of alumina and silica as reinforcement due to discontinues protective film in addition to increasing in temperatures at 10 % HCl solution, it reached (8.252 mpy) by reinforced with SiC. Alumina was exhibited corrosion resistant better than
SiC due to it is insulator; galvanic corrosion occurs when incorporation of semiconductor SiC only. Specimens were exposed to NaOH solution, aluminum reinforced with Al2O3 and SiC appears poor corrosion resistance. Finally, the results of effect NaCl were investigated, appeared an increase in corrosion rate with increasing in time.

Studying and Modeling The Effects of Quartz Addition and Heat Treatment on Corrosion Properties of Ceramic Coating

Ali H. Ataiwi; Ibtihal A. Mahmood; Jabbar H. mohmmed

Engineering and Technology Journal, 2011, Volume 29, Issue 12, Pages 2564-2579

In this work, a new glass-ceramic coating has been developed and applied, as a single coat without prior chemical treatment of the surface, by using the dipping technique on metal substrate. the coating are designed for application on varies grades of low alloy steel, the selected substrate was low carbon low alloyed steel with (0.2)%C. Various heat treatments at temperatures ( 500,550, and 600˚C ) at different times (60 & 120)min and with quartz addition in the range (0-15)% were used to obtain a glass-ceramics that have the optimum coating properties. These coating have been characterized by x-ray diffraction analyses and the results showed presence of a number of microcrystalline phases which are formed during the heat treatments. The results of corrosion resistance tests indicated that the acid resistance was greatly improved by addition of quartz into enamel frit but at same times decreased the alkali corrosion resistance, while the heat treatments improved both acid and alkali resistance for all cases, this is attributed to the formation of complex network from crystalline phases. The results also indicated that the heat treatment at 600˚C for 120min with 15% quartz addition brought the optimum values for acid resistance property which are improved by 86.66%, while the optimum values for alkali resistance property was brought with free quartz added samples which were treated at 600˚C for 120min. Mathematical modeling is implemented and regression equations are obtained by using ( SPSS ) software to predict the experimental data for acid and alkali corrosion rate. Comparing the predicted and measured values gives high prediction accuracy. The accuracy of prediction has been (82.58%, and 96.7%) for acid and alkali resistance properties respectively.

Effect of the Heat Treatments on Corrosion and Erosion-Corrosion for Carbon Steel

Muna k.Abbass; Mohammed A.Ahmed; Makarem Hazem

Engineering and Technology Journal, 2011, Volume 29, Issue 13, Pages 2706-2722

The aim of present work is to study the effect of different heat treatments [full annealing ,normalizing ,and hardening and tempering at (300C° ,600C°)] on general corrosion and erosion-corrosion for a carbon steel type (C35) in 3.5wt% NaCl solution as corrosive medium for general corrosion while in erosion-corrosion ,slurry with 1wt% SiO2 sand was added to 3.5wt% NaCl solution as the erodent. The experimental work tests were done using special device which was designed and manufactured according to (G73 ASTM) using traditional weight loss technique to measure weight loss rate or corrosion rate in (gmd) unit.
It was found that the general corrosion rates for all heat treated specimens were lower than erosion-corrosion rate. The erosion-corrosion rate of specimen which was quenched and tempered at 600C° was found smaller than other heat treated specimens The normalizing heat treatment of low carbon steel improves the general pure corrosion resistance after immersion 20 day in 3.5 wt% NaCl solution.