Study on the corrosion behaviors of high-silicon chromium iron in acidic and alkaline soil solutions

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kechen Lv ◽  
Xinyu Yang ◽  
Tangqing Wu ◽  
Song Xu ◽  
Lanlan Liu ◽  
...  
Keyword(s):  
Soil Solution ◽  
Corrosion Behavior ◽  
Material Selection ◽  
Southern China ◽  
Acid Soil ◽  
Alkaline Soil ◽  
Content Type ◽  
Soil Solutions ◽  
High Silicon ◽  
Corrosion Pits

Purpose High-silicon chromium iron (HSCI) has been used in ground grids in southern China, while there was a lack of study on its corrosion behavior in this soil environment. The purpose of this paper is to discover the corrosion of HSCI in acidic and alkaline soil solutions. Design/methodology/approach The original defects on the HSCI surface were observed using optical microscopy, and the corrosion behavior of the HSCI in the acidic and alkaline soil solutions were jointly detected using electrochemical measurements and scanning electron microscopy/energy dispersive spectrometer. Findings The results showed the corrosion rates of the HSCI in the acidic and alkaline soil solutions were limited, and the high contents of Cr and Si in matrix was responsible for its high corrosion resistance. The HSCI showed a similar corrosion tendency in the two solutions, while its corrosion rate in the acid soil solution was higher than that in the alkaline soil solution. The corrosion pits on the specimen surface were originated from the original defects in matrix, and the edges of the corrosion pits were more rounded than the original defects after 720 h immersion in the two solutions. The original defects in the HSCI matrix played a significant role in the corrosion process. Originality/value The paper discovered the corrosion evolution of HSCI in the acidic and alkaline soil solutions. What is more, the acceleration role of the original defects on the corrosion of the HSCI in the acidic and alkaline soil solutions was discovered in the paper. The results are beneficial for the material selection of ground grid equipment in engineering.

Corrosion of copper exposed to Zhanjiang and Zhuhai atmospheric environments

2017 ◽  
Vol 64 (3) ◽  
pp. 286-292 ◽  
Author(s):  
Wei Su ◽  
Wangyan Lv ◽  
Zhengchun Liu ◽  
Zengguang Zhang
Keyword(s):  
Corrosion Behavior ◽  
Material Selection ◽  
Southern China ◽  
Coastal Region ◽  
Exposure Period ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Exposure Site ◽  
One Year

Purpose The aim of this paper was to study the initial corrosion behavior of copper in the substations of Zhanjiang and Zhuhai. Design/methodology/approach The copper exposed at the substation of Guangdong coastal region in southern China for up to 12 months. The rust layer formed on the copper has been examined by scanning electron microscopy, X-ray energy spectrum, X-ray diffraction and electrochemical polarization techniques. Findings The corrosion weight loss of copper at Zhanjiang exposure site is a little more serious than that at Zhuhai exposure site in every exposure period. The corrosion products of copper have different changes in color and composition at the two exposure sites. The tensile strength of copper has a slight decrease after one-year exposure. Originality/value The atmospheric exposure experiments of copper in the substations of Zhanjiang and Zhuhai have been adopted for the first time. The corrosion behavior of copper was investigated, and it can provide reference for material selection of the substation.

Speciation of cadmium in soil solutions of saline/sodic soils and relationship with cadmium concentrations in potato tubers (Solanum tuberosum L.)

Soil Research ◽  
1997 ◽  
Vol 35 (1) ◽  
pp. 183 ◽  
Author(s):  
M. J. McLaughlin ◽  
K. G. Tiller ◽  
M. K. Smart
Keyword(s):  
Soil Solution ◽  
Soil Ph ◽  
Solanum Tuberosum L ◽  
Alkaline Soil ◽  
Sodic Soils ◽  
Chloro Complexes ◽  
Soil Solutions ◽  
High Concentrations ◽  
The Stability ◽  
Saline Solutions

Fifty commercial potato crops and associated soils were sampled. Soil solutions were extracted from rewetted soils by centrifugation, and solution composition was related to Cd concentrations in tubers. Soils were also extracted with 0·01 M Ca(NO3)2 and 0·01 M CaCl2 solutions, and Cd2+ activities in the extracts were calculated by difference using the stability constants for formation of CdCl2-nn species. The soils had saline solutions (>4 dS/m), and Cl- and SO2-4 in solution markedly affected the speciation of Cd in soil solution, with chloro-complexes, in particular, dominating. While low soil pH was associated with high (>25 nM) concentrations of Cd in soil solution, chloro-complexation also led to high concentrations of Cd in solution, even at neutral to alkaline soil pH values. Tuber Cd concentrations were not related to activities of Cd2+ in soil solution or to activities in dilute salt extracts of soil. Tuber Cd concentrations were related to the degree of chloro-complexation of Cd in solution. The relationship of tuber Cd concentrations to chloro-complexation in soil solution suggests that Cd species other than the free Cd2+ ion are involved in the transport through soil and uptake of Cd by plants.

The corrosion behavior of chromated AA2024 aluminum alloy in 3.5% NaCl solution

2019 ◽  
Vol 66 (6) ◽  
pp. 879-887 ◽  
Author(s):  
Yong Zhou ◽  
Pei Zhang ◽  
Jinping Xiong ◽  
Fuan Yan
Keyword(s):  
Aluminum Alloy ◽  
Grain Boundary ◽  
Corrosion Behavior ◽  
Electrochemical Measurement ◽  
Nacl Solution ◽  
Content Type ◽  
Chromate Conversion Coating ◽  
Chromate Coating ◽  
Corrosion Mechanisms ◽  
Corrosion Pits

Purpose A chromate conversion coating was prepared on the surface of bare AA2024 aluminum alloy by direct immersion in the chromating treatment bath, and the corrosion behavior of chromated AA2024 aluminum alloy in 3.5 per cent NaCl solution was studied by electrochemical measurement and microstructural observation. Design/methodology/approach According to the polarization curve test and the scanning electron microscope observation, the corrosion evolution of chromated AA2024 in 3.5 per cent NaCl solution was divided into the following three stages: coating failure, pitting corrosion and intergranular corrosion (IGC). Findings In the first stage, the chromate coating degraded gradually due to the combined action of chloride anions and water molecules, resulting in the complete exposure of AA2024 substrate to 3.5 per cent NaCl solution. Subsequently, in the second stage, chloride anions adsorbed at the sites of θ phase (Al2Cu) and S phase (Al2CuMg) on the AA2024 surface preferentially, and some corrosion pits initiated at the above two sites and propagated towards the deep of crystal grains. However, the propagation of a pit terminated when the pit front arrived at the adjacent grain boundary, where the initiation of IGC occurred. Originality/value Finally, in the third stage, the corrosion proceeded along the continuous grain boundary net and penetrated the internal of AA2024 substrate, resulting in the propagation of IGC. The related corrosion mechanisms for the bare and the chromated AA2024 were also discussed.

Effects of environmental factors on corrosion behavior of high-silicon cast iron in Shanxi soil medium

2018 ◽  
Vol 65 (6) ◽  
pp. 538-546
Author(s):  
De Ding ◽  
Yue Zhang ◽  
Xiaobing Yu ◽  
Benling Fang ◽  
Jipu Guo ◽  
...  
Keyword(s):  
Cast Iron ◽  
Corrosion Rate ◽  
Water Content ◽  
Corrosion Behavior ◽  
Chloride Concentration ◽  
Chemical Compositions ◽  
Corrosion Mechanism ◽  
Soil Medium ◽  
Content Type ◽  
High Silicon

Purpose High-silicon cast iron has excellent corrosion resistance in some specific medium. But the effects of pH value, chloride concentration and soil moisture content on corrosion behavior are still unknown. This study aims to provide reference for the application of high-silicon cast iron in different environments. Design/methodology/approach Electrochemical impedance spectroscopy and potentiodynamic polarization curves were used to investigate the corrosion mechanism and rate. The morphology was observed by scanning electron microscopy. The chemical compositions of the corrosion products were detected by energy-dispersive spectroscopy and X-ray diffraction. Findings When the solution is acidic, the corrosion of high-silicon cast iron is more serious. When the chloride concentration is 0.1 per cent, the corrosion rate of high-silicon cast iron is the largest. A passive film is formed on the surface to prevent the corrosion reaction with the increasing of chloride concentration. The corrosion rate is the largest when water content is 15 per cent, and the corrosion is the lightest when water content is 30 per cent. Originality/value This study provides support for the selection of high-silicon cast iron as grounded material.

Fractal characteristics of AC corrosion morphology of X80 pipeline steel in coastal soil solution

2019 ◽  
Vol 66 (6) ◽  
pp. 868-878
Author(s):  
Yu Fu ◽  
Jie Kou ◽  
Cuiwei Du
Keyword(s):  
Fractal Dimension ◽  
Soil Solution ◽  
Corrosion Behavior ◽  
Pipeline Steel ◽  
Three Dimensional ◽  
Uniform Corrosion ◽  
X80 Pipeline Steel ◽  
Corrosion Morphology ◽  
Content Type ◽  
X80 Steel

Purpose Pipelines are seriously corroded due to the close distance between pipelines and high voltage transmission lines. The purpose of this paper is to study the influence of alternating current (AC) on corrosion behavior of X80 pipeline steel in coastal soil solution. Design/methodology/approach The corrosion behavior of X80 steel under different AC densities in coastal soil solution was investigated by electrochemical measurements and image processing technology. Furthermore, a quantitative description model of AC corrosion through fractal dimension of corrosion image was established. Findings The results show that under low AC density the X80 steel is mainly uniform corrosion, and once AC density reaches 150 A/m2, the corrosion morphology gradually turns to pitting corrosion with irregular circle. For another aspect, the fractal dimension of corrosion images shows that the two/three-dimensional fractal dimension increase with the increase of AC density, presenting a linear and an exponential relationship respectively. In addition, the variation of the three-dimensional fractal dimension is the same as that of average corrosion rate. The threshold of the increasing trend of fractal dimension as well as corrosion type is 150 A/m2. Originality/value The investigation provides a quantitative method to describe AC corrosion morphology through fractal dimension. Furthermore, the method is of benefit to process corrosion images automatically.

The influence of tensile stress on the electrochemical behavior of X80 steel in a simulated acid soil solution

2015 ◽  
Vol 62 (2) ◽  
pp. 103-108 ◽  
Author(s):  
Jie Zhang ◽  
Jing Liu ◽  
Qian Hu ◽  
Feng Huang ◽  
ZhaoYang Cheng ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Dissolution Rate ◽  
Soil Solution ◽  
Corrosion Product ◽  
Electrochemical Behavior ◽  
Acid Soil ◽  
Content Type ◽  
Corrosion Product Film ◽  
Product Film ◽  
X80 Steel

Purpose – The aim of this paper was to clarify the influence of tensile stress on the electrochemical behavior of X80 steel in a simulated acid soil solution and attempt to understand mechanistic aspects of the corrosion behaviors of X80 under these conditions. Design/methodology/approach – The electrochemical behavior of X80 steel at various tensile stresses was investigated in a simulated acid soil solution using electrochemical impedance spectroscopy, potentiodynamic scan measurements and surface analysis techniques. Findings – The results show that as tensile stress was increased, the open-circuit potential decreased, the reaction activity increase, the reaction resistance (Rct)value became smaller by degrees, the corrosion product film resistance (Rf) first decreased and then increased and polarization current densities changed conversely. The corrosion product film was compact and continuous under the low stress, whereas it was relatively loose under high-stress conditions. Tensile stress promotes the movement of dislocations, which become active points when they move to the steel surface. The increase in the number of active points enhances the anodic dissolution rate and promotes the formation of corrosion product film whose blocking effect can decrease the dissolution rate. The corrosion rate of the specimen is determined by these two effects. Originality/value – This research provides an essential insight into the mechanism of the electrochemical behavior of X80 steel in acid soil environments.

The role of robotics in additive manufacturing: review of the AM processes and introduction of an intelligent system

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
J. Norberto Pires ◽  
Amin S. Azar ◽  
Filipe Nogueira ◽  
Carlos Ye Zhu ◽  
Ricardo Branco ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Computer Aided Design ◽  
Intelligent System ◽  
Material Selection ◽  
High Strength Steels ◽  
Industrial Applications ◽  
Layer By Layer ◽  
Content Type ◽  
Functional Components

Purpose Additive manufacturing (AM) is a rapidly evolving manufacturing process, which refers to a set of technologies that add materials layer-by-layer to create functional components. AM technologies have received an enormous attention from both academia and industry, and they are being successfully used in various applications, such as rapid prototyping, tooling, direct manufacturing and repair, among others. AM does not necessarily imply building parts, as it also refers to innovation in materials, system and part designs, novel combination of properties and interplay between systems and materials. The most exciting features of AM are related to the development of radically new systems and materials that can be used in advanced products with the aim of reducing costs, manufacturing difficulties, weight, waste and energy consumption. It is essential to develop an advanced production system that assists the user through the process, from the computer-aided design model to functional components. The challenges faced in the research and development and operational phase of producing those parts include requiring the capacity to simulate and observe the building process and, more importantly, being able to introduce the production changes in a real-time fashion. This paper aims to review the role of robotics in various AM technologies to underline its importance, followed by an introduction of a novel and intelligent system for directed energy deposition (DED) technology. Design/methodology/approach AM presents intrinsic advantages when compared to the conventional processes. Nevertheless, its industrial integration remains as a challenge due to equipment and process complexities. DED technologies are among the most sophisticated concepts that have the potential of transforming the current material processing practices. Findings The objective of this paper is identifying the fundamental features of an intelligent DED platform, capable of handling the science and operational aspects of the advanced AM applications. Consequently, we introduce and discuss a novel robotic AM system, designed for processing metals and alloys such as aluminium alloys, high-strength steels, stainless steels, titanium alloys, magnesium alloys, nickel-based superalloys and other metallic alloys for various applications. A few demonstrators are presented and briefly discussed, to present the usefulness of the introduced system and underlying concept. The main design objective of the presented intelligent robotic AM system is to implement a design-and-produce strategy. This means that the system should allow the user to focus on the knowledge-based tasks, e.g. the tasks of designing the part, material selection, simulating the deposition process and anticipating the metallurgical properties of the final part, as the rest would be handled automatically. Research limitations/implications This paper reviews a few AM technologies, where robotics is a central part of the process, such as vat photopolymerization, material jetting, binder jetting, material extrusion, powder bed fusion, DED and sheet lamination. This paper aims to influence the development of robot-based AM systems for industrial applications such as part production, automotive, medical, aerospace and defence sectors. Originality/value The presented intelligent system is an original development that is designed and built by the co-authors J. Norberto Pires, Amin S. Azar and Trayana Tankova.

Corrosion of a chrome-moly pipe transporting sulfuric acid in a demineralization section: a failure analysis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Andres Marquez ◽  
Chris Maharaj
Keyword(s):  
Sulfuric Acid ◽  
Material Selection ◽  
Real Life ◽  
Main Idea ◽  
Petrochemical Plant ◽  
Material Loss ◽  
Corrosion Failure ◽  
Content Type ◽  
Characterization Methods ◽  
X Ray

Purpose The purpose of this study was to carry out an analysis of the corrosion failure on a chrome-moly pipeline transporting highly concentrated sulfuric acid in a demineralization section at a petrochemical plant, along with the feasibility of using inhibitors to minimize the corrosive effects of sulfuric acid. Design/methodology/approach X-ray fluorescence spectroscopy, high-resolution optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and accelerated corrosion experiments (ACE) were performed. Findings Erosion-corrosion failure was confirmed by the significant reduction in thickness of the internal surface of the material exposed to sulfuric acid, as well as the formation of an oxide scale/layer. ACE accurately predicted high material loss from exposure to sulfuric acid. Moreover, adding ascorbic acid as a corrosion inhibitor (even at low concentrations) was found to reduce the oxidation by more than 50% in the presence of sulfuric acid. Originality/value The main idea/purpose of this work relies on the analysis of recurrent real-life corrosion-attributed failures that are common in industry but are not properly addressed for a variety of reasons, poor management and lack of corrosion preventive strategies being the main ones. This study once again highlights readily available solutions/implementations that are capable of not only addressing technically the issue investigated but also, and as important, economically. By using microscopic imaging, reliable well-tested and widely used characterization methods, all combined with basic experiments and tests, the nature of the repetitive failure investigated was clearly demonstrated as well as readily available alternatives to minimize it in the short term. Nevertheless, implementing material selection techniques appropriately as effective corrosion prevention/control and cost-saving strategies must be enforced in any process.

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