Corrosion Activity of Operating Conditions for the Steel Equipment and Pipelines in the Plants Extracting CO2-Containing Gases

Metallurgist ◽  
2021 ◽  
Author(s):  
R. K. Vagapov ◽  
D. N. Zapevalov
Keyword(s):  
Operating Conditions ◽  
Corrosion Activity ◽  
Steel Equipment ◽  
Equipment And Pipelines

Study of hydrogenation and corrosion of steel equipment and pipelines at the production facilities of H2S -containing hydrocarbon raw materials

2021 ◽  
pp. 170-181
Author(s):  
R. K. Vagapov
Keyword(s):  
Raw Materials ◽  
Strength Properties ◽  
Point Of View ◽  
Low Alloy Steels ◽  
Safety And Reliability ◽  
Alloy Steels ◽  
Steel Equipment ◽  
Equipment And Pipelines ◽  
Corrosion Of Steel ◽  
The Impact

The impact of hydrogen sulfide raw materials on steel equipment and pipelines is associated not only with corrosion processes, but also with the hydrogenation of used carbon and low-alloy steels. This can lead to the loss of their strength properties and the subsequent destruction of equipment operated under conditions of increased operating pressures. Such corrosive-mechanical effects associated with the penetration of hydrogen into steel are the most dangerous from the point of view of the safety and reliability of the operation of facilities for the production of hydrocarbon fluids. The effect of H2S on the main types of structural steels was investigated according to the results of autoclave tests. The formation of blistering (blistering) and cracks on the surface of steels due to the effect of hydrogen on the steel was recorded. A study of the phase composition of corrosion products and their possible effect on the processes of corrosion and hydrogenation of steel has been carried out.

scholarly journals Influence of chemical additives on the properties of polymer foams

2018 ◽  
Vol 251 ◽  
pp. 01017
Author(s):  
Michail Bruyako ◽  
Larisa Grigoreva ◽  
Stepan Lvov
Keyword(s):  
Thermal Insulation ◽  
Stannous Chloride ◽  
Acid Number ◽  
Operating Conditions ◽  
Corrosion Activity ◽  
Chemical Additives ◽  
Insulating Materials ◽  
Wide Range ◽  
Strength And Durability ◽  
Foam Plastics

Products based on thermosetting plastics have a variety of applications. One of the directions is thermal insulation. Filling foams provide excellent thermal insulation, due to the most optimal ratio of weight, strength and durability. Such heat-insulating materials work in a wide range of operating conditions. The article presents data on the study of the effect of chemical additives on the reduction of the acid number and the reduction in the corrosivity of foam plastics. The greatest efficiency in reducing corrosion activity has composition based on dihydrate of stannous chloride (II) with calcium oxide in a ratio of 2: 0.5. The data on the change in the multiplicity of foaming when introducing chemical additives containing the same name cation and an anion of the same name are presented.

Degradation/Damage Modes and their Control Measures for Stainless Steel Components in Chemical Plants

2013 ◽  
Vol 794 ◽  
pp. 681-690
Author(s):  
Masao Nakahara
Keyword(s):  
Stainless Steel ◽  
Operating Conditions ◽  
Control Measures ◽  
Chemical Plants ◽  
Life Estimation ◽  
Materials Engineering ◽  
Control And Prevention ◽  
Steel Equipment ◽  
Degradation Of Materials ◽  
Reactive Metals

Safe and continuous operation of chemical plants is the most important issue for sustainability of chemical enterprises. The control and prevention of degradation/damage on components used in chemical plants are indispensable for this purpose. Although varied types of material, such as stainless steels, Ni-based alloys and reactive metals, are in use to control these phenomena in plants, various cases of degradation/damage have actually been experienced and the accidents caused by such degradation have occasionally been reported. In order to prevent such uncontrolled degradation, it is thought necessary to predict the likelihood of degradation of materials under actual operating conditions, to use compatible materials, to detect the degradation by inspection in advance and to apply proper countermeasures based on realistic life estimation of the plant concerned. In order to follow these processes properly, extensive accumulation and orderly organization of knowledge about the mechanisms on degradation/damages, characteristics of materials, inspection technics and methods of plant life estimation are thought of vital importance. As stainless steel is the commonly used material in chemical plants, sufficient accumulation of informattion and knowledge about the stainless steel components to be used is considered the most important subject to prevent the degradation/damage in chemical plants. This paper enumerates the characteristics of commonly encountered modes of degradation with stainless steel components in chemical plants and presents some cases of the degradation/damage on stainless steel equipment in plants, together with control measures required to prevent such degradation. The present-day problems of materials engineering relating to the reliability of chemical plants and the countermeasures against degradation/damage are also presented.

Monitoring of technological environments at petrochemical plants as a means of ensuring their safe operation

2021 ◽  
pp. 162-168
Author(s):  
R. N. Bahtizin ◽  
◽  
S. N. Zubin ◽  
A. B. Laptev ◽  
D. A. Laptev ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Regression Model ◽  
Oil Refining ◽  
Circulation System ◽  
Corrosion Activity ◽  
Divalent Metal Ions ◽  
Recycled Water ◽  
Reservoir Water ◽  
Evaporation Coefficient ◽  
Equipment And Pipelines

The cooling recycled water of petrochemical enterprises is characterized by high corrosion activity, unstable composition and, due to the evaporation of water in cooling towers, a constant increase in the concentration of dissolved salts, suspended particles and organic pollutants. Some of the salts formed by divalent metal ions fall out in the form of deposits, and the water is satu-rated with chlorine, sulfate, phosphate, and carbonations and becomes corrosive. At the same time, the corrosion activity of reservoir water varies widely depending on the saturation of cer-tain ions and other ingredients. It is established that monitoring the composition of recycled water and determining the corrosion rate of equipment and pipelines, carried out within 1-2 months, allow us to build a regression model of the dependence of the corrosion rate on the technical parameters of water, with which we can accurately calculate the values of the corrosion rate on the evaporation coefficient. Monitoring of technological environments and optimization of their composition through mathematical modeling will significantly improve the safety of equipment and pipelines operation at oil refining enterprises. Keywords: corrosion inhibitor; scale inhibitor; biocide; water circulation system; evaporation coefficient; monitoring; cooling water; regression model.

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Slow-scan CCD cameras and low-dose High-Resolution Electron Microscopy: Direct and quantitative

1994 ◽  
Vol 52 ◽  
pp. 412-413
Author(s):  
M. Pan
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Damage ◽  
Low Dose ◽  
Dynamic Range ◽  
High Resolution Electron Microscopy ◽  
Operating Conditions ◽  
Digital Data ◽  
Ccd Cameras ◽  
Resolution Electron

It has been known for many years that materials such as zeolites, polymers, and biological specimens have crystalline structures that are vulnerable to electron beam irradiation. This radiation damage severely restrains the use of high resolution electron microscopy (HREM). As a result, structural characterization of these materials using HREM techniques becomes difficult and challenging. The emergence of slow-scan CCD cameras in recent years has made it possible to record high resolution (∽2Å) structural images with low beam intensity before any apparent structural damage occurs. Among the many ideal properties of slow-scan CCD cameras, the low readout noise and digital recording allow for low-dose HREM to be carried out in an efficient and quantitative way. For example, the image quality (or resolution) can be readily evaluated on-line at the microscope and this information can then be used to optimize the operating conditions, thus ensuring that high quality images are recorded. Since slow-scan CCD cameras output (undistorted) digital data within the large dynamic range (103-104), they are ideal for quantitative electron diffraction and microscopy.

Simulation and Contrast Analysis of tem Images of Cracks

1990 ◽  
Vol 48 (1) ◽  
pp. 578-579
Author(s):  
D. Goyal ◽  
A. H. King
Keyword(s):  
Displacement Vector ◽  
Crack Tip ◽  
Perfect Crystal ◽  
Operating Conditions ◽  
Displacement Fields ◽  
Fringe Contrast ◽  
Orthogonal Geometry ◽  
Moire Fringe ◽  
Moiré Fringe

TEM images of cracks have been found to give rise to a moiré fringe type of contrast. It is apparent that the moire fringe contrast is observed because of the presence of a fault in a perfect crystal, and is characteristic of the fault geometry and the diffracting conditions in the TEM. Various studies have reported that the moire fringe contrast observed due to the presence of a crack in an otherwise perfect crystal is distinctive of the mode of crack. This paper describes a technique to study the geometry and mode of the cracks by comparing the images they produce in the TEM because of the effect that their displacement fields have on the diffraction of electrons by the crystal (containing a crack) with the corresponding theoretical images. In order to formulate a means of matching experimental images with theoretical ones, displacement fields of dislocations present (if any) in the vicinity of the crack are not considered, only the effect of the displacement field of the crack is considered.The theoretical images are obtained using a computer program based on the two beam approximation of the dynamical theory of diffraction contrast for an imperfect crystal. The procedures for the determination of the various parameters involved in these computations have been well documented. There are three basic modes of crack. Preliminary studies were carried out considering the simplest form of crack geometries, i. e., mode I, II, III and the mixed modes, with orthogonal crack geometries. It was found that the contrast obtained from each mode is very distinct. The effect of variation of operating conditions such as diffracting vector (), the deviation parameter (ω), the electron beam direction () and the displacement vector were studied. It has been found that any small change in the above parameters can result in a drastic change in the contrast. The most important parameter for the matching of the theoretical and the experimental images was found to be the determination of the geometry of the crack under consideration. In order to be able to simulate the crack image shown in Figure 1, the crack geometry was modified from a orthogonal geometry to one with a crack tip inclined to the original crack front. The variation in the crack tip direction resulted in the variation of the displacement vector also. Figure 1 is a cross-sectional micrograph of a silicon wafer with a chromium film on top, showing a crack in the silicon.

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