"Corrosion Investigation of Stainless Steel and Stainless Steel Clad Reinforcing Bars"
In severely corrosive environments such as Eastern Province of Saudi Arabia, structures are exposed to industrial marine conditions and highly corrosive groundwater, specially at sabkha formations. The research conducted on the structures in this region during the last three decades established that reinforced concrete structures constructed using conventional concrete and carbon steel bar undergo corrosion induced deterioration within ten years after construction. Premature deterioration of reinforced concrete structures cause dearly to countries’ economies. For instance, the latest estimate of the annual cost of corrosion to the highway bridges alone in the USA, including steel and concrete, is $8.3 billion.
To assure a 100-year service life, use of stainless steel-clad reinforcement is being specified. Stainless steel-clad reinforcement combines a stainless steel outer layer with a carbon steel core to provide the benefits of stainless steel at a reasonable cost.
The objective of the proposed investigation is to evaluate corrosion performance of solid stainless steel, stainless steel clad, and MMFX bars, in the laboratory. Reinforced concrete lab specimens will be prepared with varying concentration of chloride and sulfate contamination. They will be tested for corrosion initiation and propagation. The laboratory study will also involve an accelerated corrosion of steel specimens in salt solutions contaminated with chloride and sulfate salts at various ratios. The corrosion of the steels will be monitored using DC electrochemical techniques. Corrosion rate of each kind of steel will be determined under freely and accelerated corrosion conditions in the laboratory.
The study will involve prediction of service life based on the extrapolation of corrosion rates of steels determined in the laboratory conditions as well as cost comparison of different steels tested. A morphological investigation will be conducted using OM (optical microscopy) and SEM (scanning electron microscopy). Chemical analysis by EDS (energy dispersive spectroscopy) and/or FTIR (Fourier Transform Infrared Spectroscopy) will also be conducted, as deemed necessary. AC impedance spectroscopic studies will be carried out with limited number of corrosion specimens to understand the mechanism of corrosion.
p.s. This is a funded project, payment for the student and for technician help is available.
"Alloying of Carbon Steel to Improve its Corrosion Resistance in Atmosphere"
Carbon steel produced by local industries has one main disadvantage that it develops brown discoloration on the surface due to corrosion upon atmospheric exposure in stock yards. Surface discoloration of steel products affect the sales, naturally. One way of getting rid of the discoloration problem is to modify composition of the local carbon steel with minute additions of appropriate alloying elements such that the price of the steel will not be affected.
The research has shown that alloying elements such as P, Cu, Ni, and Cr increase corrosion resistance of weathering steels. In the proposed research, the locally produced steel will constitute the basis of the study. Objective is to improve corrosion resistance of the steel to atmospheric exposure in this environment. For this purpose, the steel will be alloyed with varying amounts of P, Cu, Ni and Cr and tested for corrosion resistance using electrochemical corrosion measurement techniques in the laboratory. The research will be continued until most cost effective alloy steel with acceptable corrosion resistance can be obtained.
"Evaluation of Coating Systems to Prevent Corrosion of Poles in Distribution Overhead Network"
Service life of steel and wood poles in different areas in Saudi Arabia is shortened due to severe corrosivity of the environment caused by abundance corrosive species in soil, groundwater and atmosphere. This leads to collapse of the poles prematurely much earlier than their design life. This is a serious problem faced by electricity companies in Saudi Arabia.
Therefore, the objective of this proposed research is to identify best performing coating system that protects poles against corrosive action of environment in Saudi Arabia.
Following a thorough literature review, several coating systems will be selected for testing in laboratory and field. The selected coating systems will be subjected to accelerated testing in the laboratory using salt spray chamber (SSC) in accordance with ASTM standard procedures. The performance of each coating system will be evaluated utilizing electrochemical corrosion monitoring methods. Three or four of the best performing coating systems in the accelerated tests will be exposed to severely corrosive environmental conditions at Jubail Industrial City (JIC), which combines both marine and industrial atmospheres. Coated panel specimens will be exposed to underground and above ground environments. They will be subjected to thorough inspection, test and analysis to determine their performance under field conditions. The investigations will be done according to ASTM standards, and will also involve the use of techniques such as SEM, EDS, XRD, FTIR, and/or AC impedance.
"Assessment of Inhibitor Effectiveness for Carbon Dioxide Corrosion (Sweet Corrosion) in Oil/Gas Industry"
Corrosion problems related to carbon dioxide (CO2) in the produced fluids have been a source of failure in production equipment. Damages have been observed in down-hole equipment, tubings, flowlines between the well-head and the process unit and in the process unit itself. The problems are caused by the corrosive effect of carbonic acid produced from the dissolution of carbon dioxide gas in water phases.
The objective of this project is to investigate an effective inhibitor system that will reduce or prevent CO2-induced corrosion (sweet corrosion) in oil/gas production facilities.
The methodology of investigation will include laboratory tests at high temperature and pressure conditions in autoclave, rotating disc tests to elucidate effect of flowing fluid on corrosion, and recirculating loop tests. The tests will be carried out using simulated down-hole solutions with and without inhibitors.
The specimens, before and after corrosion tests with and without inhibitors, will be evaluated by gravimetric weight-loss method and electrochemical techniques for determination of corrosion rate and effectiveness of inhibitors. In addition, SEM, EDS, FTIR, and/or NMR methods will be utilized to study the chemistry of corrosion reactions and morphology of corroding specimens.
The results will be of great significance for oil/gas producing industry such as Saudi Aramco.