Atmospheric Corrosion State Evaluation Based on Surface Corrosion Morphology for Electrical Metal Frame Equipment in Chongqing Power Grid

2019 ◽  
Vol 815 ◽  
pp. 89-95 ◽  
Author(s):  
Gao Lin Wu ◽  
Yao Zhong ◽  
Xiao Ren ◽  
Jian Hao ◽  
Qian Wang ◽  
...  
Keyword(s):  
Atmospheric Corrosion ◽  
Power Transmission ◽  
Electrical Equipment ◽  
Test Method ◽  
Metal Corrosion ◽  
Atmospheric Environment ◽  
Corrosion Morphology ◽  
Surface Corrosion ◽  
Metal Frame ◽  
Corrosion State

This paper studies the atmospheric corrosion characteristics of grid metal frame equipment in Chongqing. Through the standard field test method of atmospheric corrosion -"exposure" method, this study carried out the substation site hanging test of the Q235 steel of the power transmission and transformation engineering structural material in the atmospheric environment, and mastered the corrosion data of Q235 steel in different corrosion stages. It was found that the morphology, quantity and characteristics of corrosion products on the metal surface varied greatly with the progress of corrosion. According to the metal corrosion morphology of different corrosion time, combined with image processing technology and wavelet transform algorithm, the parameters such as gray mean M, corrosion standard deviation σm, corrosion energy E, and energy percentage of wavelet image coefficient were selected as corrosion characteristic variable. At the same time, the BP neural network algorithm was used to qualitatively evaluate the corrosion state of the electrical equipment metal. By testing the on-site samples of the two substations, the corrosion state values of the samples were 0.946 and 0.8071, respectively, which is consistent with the actual corrosion degree, and the system had a good evaluation result.

An accelerated testing method for the evaluation of atmospheric corrosion resistance of weathering steels

2015 ◽  
Vol 62 (2) ◽  
pp. 77-82 ◽  
Author(s):  
Yuhai Qian ◽  
Jingjun Xu ◽  
Meishuan Li
Keyword(s):  
Corrosion Resistance ◽  
Atmospheric Corrosion ◽  
Test Methods ◽  
Test Method ◽  
Atmospheric Environment ◽  
Weathering Steel ◽  
Content Type ◽  
Dry Process ◽  
Immersion Medium ◽  
Short Period

Purpose – The purpose of this paper is to present a laboratory accelerated periodic immersion wet/dry cyclic corrosion test, reflecting the alternate wet/dry process during the atmospheric exposure of metallic materials, which can be applied to evaluate the atmospheric corrosion resistance (ACR) of weathering steels in a very short period. Design/methodology/approach – This test method uses 0.01 M sodium bisulfite aqueous solution with pH 4.4 as the immersion medium, simulating the notable characteristics of sulfur dioxide pollutant in industrially polluted atmospheres. During the test process, the tested specimens are immersed into the solution for 12 minutes, immediately followed by the subsequent drying process for 48 minutes, and such alternate process consists of a cyclic period, i.e. 1 hour. As a result of this procedure, a relative corrosion rate is defined to determine the ACR. To determine a preferred test period, different test periods including 72 and 200 hours were compared. Findings – Compared with several other commonly used test methods, it was confirmed that the relative ACR of various steels can be determined after testing for only 72 hours. The constituent of the corrosion products, i.e. the rust layer, was consistent with that formed after long-term exposure in a typical outdoor atmospheric environment. Originality/value – The test method enables comparative testing for ranking the ACR of weathering steel during the development of new weathering steels.

An examination of the surface corrosion state of dental fillings and constructions.

1986 ◽  
Vol 13 (3) ◽  
pp. 235-246 ◽  
Author(s):  
B. HÅKANSSON ◽  
E. YONTCHEV ◽  
N.-G. VANNERBERG ◽  
B. HEDEGÅRD
Keyword(s):  
Surface Corrosion ◽  
Dental Fillings ◽  
Corrosion State

Novel Chromium-Free Technologies for the Prevention of Wet Stack Corrosion on Hot Dipped Metallic Coatings: A Review

CORROSION ◽  
10.5006/2772 ◽  
2018 ◽  
Vol 74 (8) ◽  
pp. 918-935
Author(s):  
Thomas Jurak ◽  
Sina Jamali ◽  
Yue Zhao ◽  
Joe Williams ◽  
Abhishek Saxena ◽  
...  
Keyword(s):  
Atmospheric Corrosion ◽  
Corrosion Inhibitors ◽  
Steel Strip ◽  
Sol Gel ◽  
Earth Metal ◽  
Ultra Violet ◽  
Metal Corrosion ◽  
Metallic Coatings ◽  
Ultra Violet Radiation ◽  
Smart Coatings

Advances in novel corrosion prevention technologies, including organic-inorganic hybrid sol-gel coatings, ultra violet radiation curable coatings, rare earth metal corrosion inhibitors, and other additions for the fabrication of smart coatings, and their potential application to hot dipped metallic coated steel strip products have been reviewed. Rather than exploring the prevention of atmospheric corrosion as in similar publications in the field, the authors have instead placed emphasis on the feasibility of the technologies for protection against “wet stack corrosion,” also known as wet storage staining. Such corrosion of hot dipped metallic coatings is a common problem in industry, but one rarely explored in academia.

scholarly journals Evaluation of stabilization of steel surface corrosion by paints

2005 ◽  
Vol 53 (5) ◽  
pp. 31-38
Author(s):  
Aleš Dvořák ◽  
Marta Ščerbejová
Keyword(s):  
Standardized Tests ◽  
Laboratory Experiments ◽  
Steel Surface ◽  
Water Soluble ◽  
Test Method ◽  
Surface Corrosion ◽  
Steel Surfaces ◽  
Micro Analysis ◽  
Sem Test

This article deals with laboratory experiments focused on protective and stabilizing effects of paints designed to protect rusted steel surfaces. Two well-known paints (the Hammerite No.1 Rustbeater synthetic paint and the Antirezin water-soluble paint) have been evaluated. The standardized tests according to ČSN have been used for the evaluation. Stabilization of rusted steel surface hasn’t been demonstrated during the tests. The SEM test method that covers micro-analysis of elements has been used for the evaluation as well.

Relay protection and automation of electric power systems

2021 ◽  
Author(s):  
Sergey Goremykin
Keyword(s):  
Power Systems ◽  
Electric Power ◽  
Transmission Lines ◽  
Power Supply ◽  
Power Transmission ◽  
Relay Protection ◽  
Electrical Equipment ◽  
Electric Power Systems ◽  
Federal State ◽  
Advantages And Disadvantages

The textbook describes the main issues of the theory of relay protection and automation of electric power systems. The structure and functional purpose of protection devices and automation of power transmission lines of various configurations, synchronous generators, power transformers, electric motors and individual electrical installations are considered. For each of the types of protection of the above objects, the structure, the principle of operation, the order of selection of settings are given, the advantages and disadvantages are evaluated, indicating the scope of application. The manual includes material on complete devices based on semiconductor and microprocessor element bases. The progressive use of such devices (protection of the third and fourth generations) is appropriate and effective due to their significant advantages. Meets the requirements of the federal state educational standards of higher education of the latest generation. It is intended for students in the areas of training 13.03.02 "Electric power and electrical engineering" (profile "Power supply", discipline "Relay protection and automation of electric power systems") and 35.03.06 "Agroengineering" (profile "Power supply and electrical equipment of agricultural enterprises", discipline "Relay protection of electrical equipment of agricultural objects"), as well as for graduate students and specialists engaged in the field of electrification and automation of industrial and agrotechnical objects.

Electrolytic accelerated corrosion morphology for structural steel based on an improved solution

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Qi Si ◽  
Yang Ding ◽  
Liang Zong
Keyword(s):  
Structural Steel ◽  
Atmospheric Corrosion ◽  
Fractal Theory ◽  
Salt Spray ◽  
Neutral Salt ◽  
Mixed Solution ◽  
Corrosion Morphology ◽  
Accelerated Corrosion ◽  
Electrolytic Corrosion ◽  
Surface Morphologies

Abstract Atmospheric corrosion degrades the mechanical properties of steel structures mainly because of stress concentrations caused by an uneven corrosion topography. Electrolytic corrosion is regarded as one of the most efficient indoor accelerated corrosion approaches, while, the uneven atmospheric corrosion topography usually cannot be well simulated by electrolytic corrosion. This study aims to introduce an electrolytic corrosion solution suitable for simulating atmospheric corrosion. The surface morphologies of the structural steel specimens after electrolytic corrosion in three different solutions under various electrification time and magnitude of the current were compared. The surface characteristics of the corroded steel plates were measured by a 3D noncontact surface topography scanner, and analyzed based on surface roughness theory and fractal theory. The results showed that the mixed solution of 0.5% CH3COONa and 0.2% NaCl will produce pitting corrosion on the steel surface, and the surface morphologies of the steel specimens after electrolytic corrosion were consistent with that of neutral salt spray accelerated corrosion test. It is verified that the electrolytic accelerated corrosion in such a solution can simulate actual atmospheric corrosion reasonably.

scholarly journals Application of An Electrical Resistance Sensor-Based Automated Corrosion Monitor in the Study of Atmospheric Corrosion

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1065 ◽  
Author(s):  
Zhuolin Li ◽  
Dongmei Fu ◽  
Ying Li ◽  
Gaoyuan Wang ◽  
Jintao Meng ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Atmospheric Corrosion ◽  
Continuous Measurement ◽  
Atmospheric Environment ◽  
Corrosion Monitoring ◽  
Metallic Materials ◽  
Actual Environment ◽  
The Internet Of Things ◽  
Corrosion Monitor ◽  
Corrosion Data

An automated corrosion monitor, named the Internet of Things atmospheric corrosion monitor (IoT ACM) has been developed. IoT ACM is based on electrical resistance sensor and enables accurate and continuous measurement of corrosion data of metallic materials. The objective of this research is to study the characteristics of atmospheric corrosion by analyzing the acquired corrosion data from IoT ACM. Employing data processing and data analysis methods to research the acquired corrosion data of steel, the atmospheric corrosion characteristics implied in the corrosion data can be discovered. Comparing the experiment results with the phenomenon of previous laboratory experiment and conclusions of previously published reports, the research results are tested and verified. The experiment results show that the change regulation of atmospheric corrosion data in the actual environment is reasonable and normal. The variation of corrosion depth is obviously influenced by relative humidity, temperature and part of air pollutants. It can be concluded that IoT ACM can be well applied to the conditions of atmospheric corrosion monitoring of metallic materials and the study of atmospheric corrosion by applying IoT ACM is effective and instructive under an actual atmospheric environment.

Computer-Aided Analysis of Oriented Crystallites by Diffraction Pattern Simulation and Tilt-Stage Control in a TEM

1997 ◽  
Vol 3 (S2) ◽  
pp. 1015-1016
Author(s):  
L.E. Thomas ◽  
L.A. Chariot ◽  
J.T. Stanley
Keyword(s):  
Small Sample ◽  
Hot Water ◽  
Metal Corrosion ◽  
Desktop Computer ◽  
Cross Sectional ◽  
Surface Corrosion ◽  
Computer Aided ◽  
Columnar Grains ◽  
Diffraction Patterns ◽  
Convergent Beam

Electron diffraction patterns taken in the transmission electron microscope (TEM) provide information about crystal structures and orientations in small sample areas. Extracting this information and manipulating local crystal orientations has become a great deal easier with the availability of desktop computer programs that allow simulation matching of experimental patterns and crystallographic control of sample tilting in the TEM. This presentation will illustrate an application of computer-aided crystallography for analyzing oriented crystallites in an experimentally complex material.The surface corrosion films that form on reactive metals such as hafnium or zirconium in hot water provided our example. Cross-sectional examinations of the corrosion films revealed a columnar microstructure of monoclinic HfO2/ZrO2 grains extending normal to the metal/corrosion-film interface.The columnar grains were only about 50 nm in width, and thus were too small to analyze individually by selected-area diffraction. Local strains in the films smeared the diffraction fine structure so there was little hope for analysis by convergent-beam diffraction methods.

Corrosion Performance of TRIP Steels under Atmospheric Environment

2019 ◽  
Vol 960 ◽  
pp. 3-8
Author(s):  
Hao Xu Wang ◽  
Yi Qin Cai ◽  
Zhuang Li ◽  
Qi Zhou
Keyword(s):  
Trip Steel ◽  
Atmospheric Corrosion ◽  
Alloying Elements ◽  
Atmospheric Environment ◽  
Protective Mechanism ◽  
Corrosion Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trip Steels ◽  
Surface Morphologies

Atmospheric corrosion test of TRIP steels was conducted in laboratory. The surface morphologies of the specimens were analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD) and electro-probe microanalysis (EPMA). Corrosion performance of TRIP steels under atmospheric environment was investigated by discussing the protective mechanism. The corrosion rates of steel A are significantly greater than steel B in atmospheric environment tests. The enhancement of corrosion performance of TRIP steel is attributed to the additions of alloying elements, such as P, Cr, Cu, and Ni etc.. The alloying elements increase the compactness and densification of rust layers. Electrochemical characteristic of TRIP steel is improved by means of the enhancement of the thermodynamic stability.

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