Corrosion Protection

In this study, the novel Ni-Al-Y2O3 nanocomposite coatings were prepared by two steps:
1)  Electrodeposition  of  Ni-Y2O3
nanocomposite  film  on  low  carbon  steel,  2)  Aluminizing  the
electrodeposited Ni-Y2O3
film using pack cementation method at 700 ˚C for 3 h. The effect of Y2O3
content  on oxidation resistance was investigated. Morphology and phase structure of the coatings
were  characterized  by  Scanning  Electron  Microscope  (SEM),  Energy  Dispersive  Spectroscope
(EDS) and X-ray Diffractometer  (XRD).  The cyclic oxidation results at 850 ˚C  for 96 h  show that
the Y
2O3
modified aluminized  coatings had  better oxidation resistance and  the parabolic oxidation
rate constant of the coatings decreased from 0.0328 to 0.0083 mg
2
.cm
-4
.h
-1
with the increase of the
Y2O3
content from 0 to 3.4 wt.%.

Crude oil is the main economic supply in many countries. Corrosion has been considered as the first fatal factor destroying the crude oil plants such as crude oil equipment, oil wells, separation vessels, storage tanks, and pipelines. This is the main reason encouraging many companies and researchers to develop new technological methods to manipulate corrosion. In this review, we discuss the types of corrosion, corrosion control methods (chemical and non-chemical methods), corrosion removal methods and corrosion monitoring process (direct and indirect measurement of corrosion). In addition some perspectives on SRB bacteria, types of inhibitors and gases removal methods were provided.

The common failures mechanisms of boiler components at elevated temperatures and monitoring techniques used in power plants to detect damaging or failures are generally well described in literature. Despite of different classification concerning the principal failure mechanisms of boiler thermal power plant components, it is necessary to emphasize that essential difference between these classification does not exist. Concerning the different failures mechanisms it is obvious that the most of them are completely explained and clear in physical sense of process but some of them are not still so explicit. Therefore, until today there is a great interest to investigate the failures of power plant boiler components especially having in mind the all peculiarities of particular events. This efforts are necessary while a full assessment of the failure mechanism(s) is required to prevent further failures due to the same causes. The numerous case studies presented in this paper were done as a contribution to this efforts.

Electrical impedance spectroscopy (EIS), in which a sinusoidal test voltage or current is applied to the sample under test to measure its impedance over a suitable frequency range, is a powerful technique to investigate the electrical properties of a large variety of materials. In practice, the measured impedance spectra, usually fitted with an equivalent electrical model, represent an electrical fingerprint of the sample providing an insight into its properties and behavior. EIS is used in a broad range of applications as a quick and easily automated technique to characterize solid, liquid, semiliquid, organic as well as inorganic materials. This paper presents an updated review of EIS main implementations and applications.

Concerns on corrosion and effective coating protection of double hull tankers and bulk carriers in service have been raised especially in water ballast tanks (WBTs). Test
protocols/methodologies specifically that which is incorporated in the International Maritime Organisation (IMO), Performance Standard for Protective Coatings for Dedicated Sea Water ballast tanks (PSPC) are being used to assess and evaluate the performance of the coatings for type approval prior to their application in WBTs. However, some of the type approved coatings may be applied as very thick films to less than ideally prepared steel substrates in the WBT. As such films experience hygrothermal cycling from operating and environmental
conditions, they become embrittled which may ultimately result in cracking. This embrittlement of the coatings is identified as an undesirable feature in the PSPC but is not mentioned in the test protocols within it. There is therefore renewed industrial research aimed at understanding this issue in order to eliminate cracking and achieve the intended coating lifespan of 15 years in good condition. This paper will critically review test protocols currently used for assessing and evaluating coating performance, particularly the IMO PSPC.

Wang, LK, Wang, MHS and Fahey, EM (2020). An innovative Lee, Massachusetts USA dissolved air flotation potable water filtration plant. In: "Evolutionary Progress in Science, Technology, Engineering, Arts, and Mathematics (STEAM)", Wang, Lawrence K. and Tsao, Hung-ping (editors). Volume 2, Number 1, January 2020; 60 pages. Lenox Institute Press, Newtonville, NY, 12128-0405, USA. No. STEAM-VOL2-NUM1-JAN2020; ISBN 978-0-9890870-3-2---------------ABSTRACT: The authors present the overall structural design, design criteria, and performance data of the two Krofta Sandfloat flotation-filtration clarifiers (DAFF; SAF-BP24) installed at the 2.0 MGD (7570 m3/day) Lee Plant in treatment of surface water for potable purposes. Lenox Institute of Water Technology (LIWT) invented and patented the innovative DAFF system, while Krofta Engineering Corporation (KEC) manufactured and installed the Lee Plant. The author also discuss (a) current corrosion control program in order to comply with the US Federal Copper and Lead Rule, and (b) the current DAF-filtration plant’s performance for removal of perchlorate, barium, sodium, disinfection by-products (DBP), total trihalomethane (THM), total haloacetic acid (HAA), microbial contaminants, turbidity, iron and manganese. The 19 years old innovative Lee DAF-filtration plant met all US Environmental Protection Agency, and the Commonwealth of Massachusetts primary and secondary drinking water standards in accordance with the 2018 Water Quality Report. The Town of Lee successfully uses zinc orthophosphate and pH adjustment to stabilize the water throughout of Lee distribution system for lead, copper and pipe corrosion control. This article has been written in memory of Dr. Milos Krofta, Dr. Donald B. Aulenbach and Dr. William A. Selke. ----------KEYWORDS: Milos Krofta, Donald B. Aulenbach, William A. Selke, Lenox Institute of Water Technology, Krofta Engineering Corporation, Dissolved Air Flotation, DAF, DAF-Filtration, DAFF, Potable Water, Backwash, Lead, Copper, Corrosion control, Zinc orthophosphate, Recommended future research, Sandfloat BP, Lee, Massachusetts, USA.

Damage of boiler tubes is a very serious problem in many utilities worldwide, including even in the most advanced countries. Preserve of boiler tube integrity present major part in maintenance programs centered to achievement of high levels of availability and reliability of thermal power plants. This is due to a very specific and complex interconnection of design and operating characteristics of the boiler unit. Based on the results of numerous boiler tube damages investigation performed on domestic thermal power plants it is concluded that the initiation of different damage mechanism was strongly influenced by tube weld geometry defects. In this paper particular attention was dedicated to this not well documented problem. Structural integrity of the boiler tubes are greatly affected by the weld excessive root penetration (melt-through) on the tube inner surface. This type of weld geometry defect, which occurred often on boiler tubing system, present local flow disruptor and also very strong stress riser. In the vicinity and downstream of excessive root penetration type disruptor initiation of different damage mechanisms (erosive and corrosive wear, under-deposit corrosion, stress corrosion, corrosion fatigue) occurred due to working fluid nucleate boiling destabilization (evaporator), or due to turbulent flow (superheater and reheater), followed by intensive suspended solids deposition.

The inhibition effect of glutaraldehyde on the corrosion of aluminum in 1.4 M HCl solution at 308-318 K was investigated by using weight loss method and characterized by Fourier Transform Infrared Spectroscopy (FTIR) & Scanning Electron Microscopic Analysis (SEM). The results show that the inhibition efficiency increases with increasing inhibitor concentration and decreases with rising temperature. The activation energy value was 20.48 kJ mol-1 for the uninhibited acid solution which increased to 33.79 kJ mol-1
in the presence of 0.1 M inhibitor concentration. Langmuir adsorption isotherm was found to provide an accurate description of the adsorption behavior of the investigated inhibitor. The thermodynamic parameters such as adsorption equilibrium constant
(Kads), free energy of adsorption (ΔGads), heat of adsorption (ΔHads) and entropy of adsorption (ΔSads) have been
calculated and discussed in detail.