Analysis of Corrosion Behavior on External Surface of 110S Tubing

2020 ◽  
Vol 993 ◽  
pp. 1242-1250
Author(s):  
Yan Han ◽  
Cheng Zheng Li ◽  
Hua Li Zhang ◽  
Yu Fei Li ◽  
Da Jiang Zhu
Keyword(s):  
Pitting Corrosion ◽  
Corrosion Test ◽  
External Surface ◽  
Sample Surface ◽  
Outer Wall ◽  
High Concentration ◽  
Surface Corrosion ◽  
Slowing Down ◽  
Threaded Connection ◽  
Acid Test

The failure analysis of 110S tubing during acidizing process was addressed. Results showed that serious pitting corrosion occurred on the outer wall of tubing, and there was no obvious pitting on the inner wall. The maximum pitting depth on the outer wall was 1019 μm. According to the results of simulation corrosion test, needle-shaped pitting appeared on the sample surface in the test without inhibitor, the maximum depth of pitting was 158 μm; and no pitting was found on the sample surface in the test within 1.5% TG501 inhibitor; the original pitting were deepened after spent acid test, and the sample with no pitting at the beginning also showed deep pitting corrosion after 96 hours spent acid test. It was indicated that the spent acid accelerated the development of pitting significantly. The external surface corrosion of the 110S tubing was caused by the chemical reaction between the high-concentration acidifying liquid and the outer wall of the tubing. There is a gap between the tubing and coupling threaded connection, which caused the acid solution entered into the thread position, and hence the severe corrosion of the thread and pin end of the tubing happened, the joint strength was continuously reduced with corrosion development till the tripping of the coupling, and then the lower string dropped. Some suggestions were proposed for avoiding or slowing down this kind of failure based on this study.

scholarly journals Effects of Saline Solutions on the Desiccation Cracking and Shrinkage Behavior of Gaomiaozi Bentonite

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Long Tan ◽  
Penglin Zheng ◽  
Qingbing Liu
Keyword(s):  
Water Content ◽  
Saline Solution ◽  
Shrinkage Strain ◽  
Sample Surface ◽  
Water Evaporation ◽  
Gmz Bentonite ◽  
Residual Water ◽  
High Concentration ◽  
Desiccation Cracking ◽  
Saline Solutions

Bentonite, when used as buffer/backfill material in the deep disposal of high-level radioactive waste (HLW), could undergo desiccation shrinkage or even cracking due to the heat released from HLW, impairing the efficiency of the barrier system. Furthermore, in-service buffer materials are inevitably in contact with the groundwater, which sometimes contain high salt concentrations. The groundwater salinity may modify the properties of bentonite and hence affect the process of desiccation and its performance. To investigate this effect, in this study, a series of temperature-controlled desiccation tests was conducted on compacted specimens of Gaomiaozi (GMZ) bentonite preliminarily saturated with two different saline solutions (NaCl and CaCl2) at the concentration varying from 0.5 to 2.0 mol/L. The experimental results indicated that, as the concentration of saline solution increases, the initial saturated water content of bentonite decreases, whereas the residual water content at the completion of the desiccation test increases. The water evaporation rate is reduced for the specimens saturated with a high-concentration saline solution, and CaCl2 has a more significant influence on water evaporation than NaCl. The evolution of cracks on the sample surface during the desiccation process can be divided into four stages: crack growth, maintenance, closure, and stabilization; an increase in the salt concentration effectively inhibits crack development. It was shown that the infiltration of saline solutions alters the microstructure of bentonite by changing the arrangement of clay particles from a dispersed pattern to more aggregate state, which results in a decrease in shrinkage strain and shrinkage anisotropy.

Finding of artisanal uses of elemental mercury in the city of Murcia in medieval times

2021 ◽  
Author(s):  
José María Esbrí ◽  
Luis Mansilla-Plaza ◽  
María Jesús Sanchez-Gonzalez ◽  
Pablo Higueras
Keyword(s):  
Atomic Absorption ◽  
Elemental Mercury ◽  
Absorption Spectrometry ◽  
Speciation Analysis ◽  
Outer Wall ◽  
High Concentration ◽  
Entire Area ◽  
High Concentrations ◽  
Under Construction ◽  
The City

<p>Mercury (Hg) was used in gilding techniques since ancient times. This metal gilding technique consisted of applying an amalgam of Au and Hg to the surface of a metallic object and then removing the Hg to achieve adhesion of the Au to the support. The traditional preparation of amalgam was a mixture of Au with Hg (in a ratio of 1/8). After this preparation, the mixture usually was ground in a mortar, heated, and then cooled by pouring it into water. The paste was applied to the areas to be browned and then the piece was subjected to mild temperatures so that the Hg evaporated, leaving a thin layer of Au on the surface of the object.</p><p>The origin of this work is the discovery of an evident quantity of liquid Hg on a site under construction, near the old wall of the city of Murcia, at a level identified as from medieval times. To elucidate the origin of this Hg, a sampling of medieval materials has been carried out throughout the site, including both the area with liquid Hg, the entire area what appears to be the work room and the adjacent rooms. The sampling has been carried out using an Ejkelkamp sampler at various depths. These soil samples were analysed by Energy Dispersion X-Ray Fluorescence using a PanAlytical device. Total Hg and Hg speciation data were obtained by Atomic Absorption Spectrometry using a Lumex equipment. In addition to this, a gaseous mercury monitoring has been carried out using a portable atomic absorption equipment to search Hg sources and gaseous Hg dispersion in the atmosphere of the studied site. Results of the survey has shown an evident and intense soil Hg pollution in a small area of 2x2 m. This affected area was located near the outer wall of the medieval building and was very restricted, which suggests that it was a storage place for liquid Hg for later use in other areas. The degassing of these recently uncovered materials produced a significant dispersion of the Hg gas throughout the enclosure. In addition to this, samples of medieval materials have shown very high concentrations of Hg in the vicinity of the contaminated area, and high concentrations in the rest of the enclosure. Speciation analysis have shown that the Hg in this part of the enclosure is in the form of metacinnabar and Hg bound to humic acids, which suggests the presence of an atmosphere with extremely high concentration of gaseous Hg in medieval times that was later deposited in the soil, being fixed to its organic phase. Multielemental analysis has shown additional high concentrations of Pb, Cu and Sn, suggesting that the artisanal works in the enclosure involved these elements too. While waiting for more specific archaeology works that can corroborate it, the origin of this Hg in the area could be the storage for the realization of gilding work on metals with this element.</p><p>This work was funded by the company “Obras y Proyectos Soyma”.</p>

Electron microscopy of the sporangium of Phytophthora capsici

1970 ◽  
Vol 48 (2) ◽  
pp. 221-227 ◽  
Author(s):  
W. T. Williams ◽  
R. K. Webster
Keyword(s):  
Plasma Membranes ◽  
Structural Changes ◽  
Phytophthora Capsici ◽  
Flagellar Apparatus ◽  
Outer Wall ◽  
Wall Layer ◽  
High Concentration ◽  
Zoospore Production ◽  
Apical Papilla ◽  
Ultrastructural Cytology

This paper reports results of a study on the ultrastructural cytology of sporangia of Phytophthora capsici Leonian with emphasis on flagellum formation, general sporangial structure during zoospore cleavage, and the presence, structure, and transition of cytoplasmic organelles and inclusions during these processes.Non-cleaving sporangial cytoplasm contains a high concentration of ribosomes, mitochondria, vacuoles, lipid inclusions, and endoplasmic reticular cisternae scattered throughout the cytoplasm. Nuclei in mature sporangia are located at the periphery of the cell, with their narrow poles aligned towards the plasma membrane. The apical papilla measures 4–5 × 10 μ, and is initiated as a fibrous third layer under the two-layered cell wall several microns from the apex. The outer wall layer surrounds the papilla while the inner wall narrows and disappears near the crown. The basal septal plug is a combination of the inner wall layer and slime substances.One of the first structural changes in the cytoplasm during zoospore cleavage is the genesis of the flagellar apparatus. Paired centrioles next to the narrow poles of the nuclei elongate to form kinetosomes which extend through the cytoplasm toward receptive axonemal vesicles. Axonemes then form in the axonemal vesicles. The terminal plate and its prisms account for the appearance of the axoneme when it forms above the terminal plate in the axonemal vesicle. The axonemal cylinder has a typical 9 + 2 morphology and the axonemal sheath is continuous with the axonemal vesicle tonoplast. The nucleus is an integral part of the flagellar apparatus and appears to be connected to the kinetid (axoneme + kinetosome) base via microtubules. Golgi dictyosomes occur in the sporangia during all stages of growth and may be responsible for elaboration of needed membranes during zoospore production. Osmiophilic droplets (liposomes), located within vacuoles, are a predominant feature of precleavage cytoplasm. These globules are probably lipid in nature. As cleavage begins, the liposomes become less opaque at the margins, and striations appear, eventually encompassing all or most of the liposomes at the time of cleavage. The liposomes then become less spherical and expand, filling the vacuoles. Electron-transparent regions eventually appear throughout the liposomes and the vacuolar membrane may disappear.Cleavage of the cytoplasm into zoospores occurs by the alignment and fusion of cleavage vesicles around individual nuclei. During this period organelles migrate to these centers. The cleavage vesicles coalesce with each other and the axonemal membranes, eventually becoming the plasma membranes of the daughter zoospores.

Effect of Artificial Aging on Intergranular Corrosion of 6063 Al Alloy

2013 ◽  
Vol 842 ◽  
pp. 275-278 ◽  
Author(s):  
Jian Ming Wang ◽  
Xiao Dan Meng ◽  
Ying Ying Bai ◽  
Guo Feng Ma ◽  
Yan Liu ◽  
...  
Keyword(s):  
Intergranular Corrosion ◽  
Corrosion Test ◽  
Artificial Aging ◽  
Al Alloy ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Accelerated Corrosion ◽  
Surface Corrosion ◽  
6063 Al Alloy ◽  
Accelerated Corrosion Test

The effect of artificial aging on the corrosion properties of 6063 Al alloy was investigated by optical microscope, field emission scanning electron microscope and accelerated corrosion test. Accelerated corrosion test revealed that the alloy was susceptible to intergranular corrosion (IGC) in the artificial aged conditions according to the surface corrosion morphology, and the IGC resistance was reduced as the aging time was prolonged, resulting from more Mg2Si grain boundary precipitates formed. However, the corroded cross-sections showed that the IGC was very local. Additionally, the surface corrosion morphology also showed that pitting corrosion took place, resulting from galvanic corrosion between (FeMn)3Si12Al15 particles and matrix Al.

Morphological Characterization of Elastin-Mimetic Block Copolymers Utilizing Cryo- and Cryoetch-HRSEM

2003 ◽  
Vol 9 (3) ◽  
pp. 171-182 ◽  
Author(s):  
Elizabeth R. Wright ◽  
Vincent P. Conticello ◽  
Robert P. Apkarian
Keyword(s):  
Block Copolymers ◽  
High Vacuum ◽  
Three Dimensional ◽  
Sample Surface ◽  
Morphological Characterization ◽  
High Concentration ◽  
Micellar Aggregates ◽  
Hydrogel Network ◽  
Resolution Level

Elastin-mimetic block copolymers were produced by genetic engineering. Genetically driven synthesis permitted control of the final physiochemical characteristics of the block copolymers. We designed BB and BAB block copolymers in which the A-block was hydrophilic and the B-block was hydrophobic. By designing the copolymers in this manner, it was proposed that they would self-assemble into micellar aggregates that, at high concentration, would form thermoreversible hydrogels. To analyze the three-dimensional fine surface morphology of the copolymers, to the resolution level of a few nanometers, we employed cryo-HRSEM. This method provided vast expanses of the specimen in its frozen hydrated state for survey. In our initial cryo-HRSEM studies, we observed the protein filaments and micelles surrounded by lakes of vitreous ice. Upon examination at low and intermediate magnifications, there was an extensive honeycomb-like filamentous network. To delineate the fine morphology of the hydrogel network at high magnification and to greater depths, we cryoetched away unbound water from the sample surface, in high vacuum, prior to chromium deposition. By using this technique, we were able to visualize for characterization purposes the fine fibril networks formed from the micellar aggregates over the surface of the hydrogel.

scholarly journals Operation corrosion test of austenitic steel bends for supercritical coal boilers

2016 ◽  
Vol 60 (1) ◽  
pp. 21-27
Author(s):  
J. Cizner ◽  
J. Hruška ◽  
J. Mlnařík
Keyword(s):  
Austenitic Steel ◽  
Brown Coal ◽  
Coal Combustion ◽  
Corrosion Test ◽  
Sample Surface ◽  
Corrosion Rates ◽  
Annealed State ◽  
Operation Conditions ◽  
Detailed Assessment

Abstract Corrosion tests of both annealed and not annealed bends of HR3C and S304H steels in operation conditions of black and brown coal combustion boilers in EPRU and EDE. After a long-term exposure, the samples were assessed gravimetrically and metallographically. The comparison of annealed and unannealed states showed higher corrosion rates in the annealed state; corrosion of the sample surface did not essentially differ for compression and tensile parts of the beams. Detailed assessment of both steels is described in detail in this study.

Failure Analysis of Cracked and Corroded Tubings in Sudong Block of Changqing Oilfield

2021 ◽  
Vol 1035 ◽  
pp. 638-646
Author(s):  
Xue Hui Zhao ◽  
Ming Xing Li ◽  
Jun Lin Liu ◽  
Man Liu
Keyword(s):  
Pitting Corrosion ◽  
Mechanical Damage ◽  
Outer Wall ◽  
Fracture Morphology ◽  
Internal Corrosion ◽  
Primary Condition ◽  
Tubing String ◽  
Result Show ◽  
Corrosion Pits ◽  
Macroscopic Analysis

In the process of layer inspection and hole mending, it was found that the corrosion of tubing in a well was serious, and perforation and fracture occurred. Part of the tubing was found to be cracked from the failed pipe samples, and relatively serious pitting corrosion pits were found on the surface of the outer wall. The fracture morphology and corrosion products were analyzed by means of macroscopic analysis and metallographic microscope, SEM and EDS. The result show that the mechanical damage of the outer wall of the tubing was the primary condition for accelerating corrosion, and the severe corrosion thinning of the inner and outer walls of the tubing was the main reason for the failure of the tubing string. The corrosion perforation of tubing was mainly caused by internal corrosion.

Studying rheological properties and reactivity of acid solutions with thickening additives

2021 ◽  
pp. 40-54
Author(s):  
M. B. Dorfman ◽  
A. A. Sentemov ◽  
I. P. Belozerov
Keyword(s):  
Rheological Properties ◽  
Acid Treatment ◽  
Reaction Rate ◽  
Acid Solutions ◽  
High Permeability ◽  
High Concentration ◽  
Sweep Efficiency ◽  
Reservoir Properties ◽  
Slowing Down ◽  
Lignosulfonic Acid

This article is the result of studies of rheological properties and reactivity of acid solutions of technical lignosulfonate, decationized lignosulfonic acid, and hydrochloric acid with the addition of lignosulfonate. Compositions that include lignosulfonate can be used as displacement agents in the development of watered layers with inhomogeneous reservoir properties. The use of thickening additives in acid solutions solves several problems. Slowing the reaction rate will allow the acid flow to leak in the reservoir deeper, with saving of acid capacity. The height viscosity of the compositions increases the sweep efficiency of the bottomhole zone by acid treatment. Due to the fact that thickening additives in the compositions have a high concentration, selective isolation of highly permeable areas of the reservoir can be realized, which, in turn, contributes to the formation of new pore channels.We evaluated the reactivity of acid solutions with thickening additives in the interaction with carbonate samples. The presence of technical lignosulfonate in an acid solution reduces the dissolution rate of samples. Slowing down the reaction rate will allow the acid composition to form long channels of high permeability, which, in turn, increases the efficiency of acid treatment.

The effect of argon and oxygen ion implantation on the physicochemical and corrosion-electrochemical properties of 14Cr17Ni2 chromium-nickel steel

2021 ◽  
Vol 4 ◽  
pp. 5-14
Author(s):  
S. G. Bystrov ◽  
◽  
S. M. Reshetnikov ◽  
E. M. Borisova ◽  
I. N. Klimova ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Pitting Corrosion ◽  
Electrochemical Behavior ◽  
Sample Surface ◽  
Local Corrosion ◽  
Nickel Steel ◽  
Original Sample ◽  
Oxygen Ion ◽  
Oxygen Ion Implantation ◽  
Corrosion Electrochemical Behavior

The effect of argon and oxygen ion implantation both in separate and joint was carried out. Physical and chemical structure of the surface and corrosion-electrochemical behavior of 14Cr17Ni2 chromium-nickel steel was studied. Methods of potentiometry, atomic force microscopy, X-ray photoelectron spectroscopy, and microhardness measurement were used. It was found that the initial chromium-nickel steel exhibits high corrosion resistance in the medium of a borate buffer solution with the addition of a local corrosion initiator — potassium sulfate. However, steel was found to be susceptible to local (pitting) corrosion in this environment. It is shown that the implantation of argon and oxygen ions changes the nature of the corrosion-electrochemical behavior of chromium-nickel steel. Treatment with Ar+ ions enriched the sample surface with Cr atoms and reduces the overall corrosion losses of steel, but is characterized by the maximum value of local corrosion. Treatment with O+ ions provide optimal results in terms of reducing local and general corrosion. It was found that in this case, the sample surface is intensively oxidized to a depth of more than 20 nm, resulting in the formation of mixed oxides that are resistant to corrosion. There is a process similar to electropolishing of the sample surface due to partial dissolution of steel. Defects in the structure of the sample surface, on which pitting corrosion began, are “healed”. Joint treatment with Ar+ ions and O+ ions does not give noticeable advantages compared to separate implantation with these ions. Corrosion losses for samples treated only with O+ ions and Ar+ ions together with O+ ions did not exceed those for the original sample, although there are practically no passivation regions on the potentiodynamic curves. Microhardness of the samples after ion implantation coincides with the microhardness of the original sample. Result of ion implantation is no significant for change in the structural and phase structure of the surface layers of chromium-nickel steel. Ion implantation will not negatively affect the physical and mechanical properties of studied steel. The research shows that it is advisable to choose the type of implantable ions and the optimal process parameters depending on the steel grade and its application. For these purposes, the research methodology proposed in this article will be useful.

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