The Corrosion Behavior of Galvanized Steel in Alkaline Soil

2013 ◽  
Vol 331 ◽  
pp. 416-420 ◽  
Author(s):  
Feng Jie Yan ◽  
Xing Geng Li ◽  
Xue Gang Wang
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Localized Corrosion ◽  
Alkaline Soil ◽  
Electrochemical Test ◽  
Accelerated Corrosion ◽  
Grounding Grid ◽  
Accelerated Corrosion Test

The grounding grid of some substation shows severely corrosion, which affects the safe running of power grid. Galvanized steel is widely used in grounding grid. However, the galvanized steel is easy to corrosion in alkaline soil. In this paper, the corrosion behavior of galvanized steel was studied through accelerated corrosion test of burying specimens in laboratory soils and the corrosion rate was measured by electrochemical test. The corrosion products and corrosion appearance were analyzed by means of SEM, and XRD. The results show that pitting corrosion and localized corrosion were observed on the surface of the galvanized steel, the corrosion products were rough and loose, indicating no protection, the corrosion products of galvanized steel were ZnO,FeO(OH),FeCl3,Zn3O(SO4)2,and ZnSO3·2.50H2O. Electrochemical test show that the corrosion rate of galvanized steel in the later corrosion stage is higher than in the initial corrosion stage.

scholarly journals Corrosion Behavior of 3% Cr Casing Steel in CO2-Containing Environment: A Case Study

2018 ◽  
Vol 11 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Lin Xu ◽  
Jie Xu ◽  
Ming-biao Xu ◽  
Si-yang Li ◽  
Shuai Liu ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Exposure Time ◽  
Corrosion Products ◽  
Localized Corrosion ◽  
Internal Corrosion ◽  
Tafel Polarization ◽  
Water Cut ◽  
Increasing Temperature

Introduction: The production casing of 3% Cr steel has encountered severe internal corrosion in Huizhou Oilfield. To disclose corrosion behavior of inner casing, a series of corrosion exposure tests were systematically conducted on 3% Cr coupons in terms of in-field conditions. Material and Methods: Influence of exposure time, temperature, and water-cut on the CO2 corrosion of 3% Cr steel was investigated, and analyses on weight loss, composition and morphology of corrosion product, and Tafel polarization curves were further carried out. Result: The results showed that the corrosion rate of 3% Cr steel increased with increasing temperature, but such trend descended when the temperature exceeded 65°C due to formation of an compact and adherent corrosion product film on the surface of 3% Cr coupons. While varying exposure time from 7 days to 14 days, the corrosion rate decreased, and the Cr and O enrichment was determined in the corrosion products. The corrosion rate of 3% Cr steel increased with a continuous increment of water-cuts, especially when the water-cut was larger than 40%. Conclusion: The localized corrosion can happen at the lower water-cut due to the presence of amorphous films. The main corrosion products were FeCO3, Cr5O12, Fe2O3, and Fe-Cr. Entry of CO2 to the simulated formation water caused an increase in the anodic Tafel slope, and accelerated dissolution of 3% Cr steel.

Effects of Deformation on Atmospheric Corrosion of Galvanized Steel

2006 ◽  
Vol 510-511 ◽  
pp. 1134-1137
Author(s):  
Jae Woong Choi ◽  
Gil Ho Hwang ◽  
Hong Rae Cha ◽  
Sung Goon Kang
Keyword(s):  
Relative Humidity ◽  
Corrosion Test ◽  
Atmospheric Corrosion ◽  
Surface Damage ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Accelerated Corrosion ◽  
Corrosion Rates ◽  
Accelerated Corrosion Test ◽  
Surface Morphologies

The effects of deformation on corrosion behavior of galvanized steel were investigated. Accelerated corrosion test was conducted under the conditions of 30oC and 90% relative humidity with flowing 200ppm sulfur dioxide gas for five weeks. Surface morphologies and corrosion products were analyzed by SEM/EDS and XRD. The corrosion products were composed of hydrates of ZnSO4. And corrosion rates of each part, bottom, bended and wall, were increased with growing strain due to surface damage and enlargement of naked surface for corrosion.

Alloy Design of New Ni-Based Structural Materials for Electrolytic Reduction and its Corrosion Behavior in Lithium Molten Salt

2014 ◽  
Vol 886 ◽  
pp. 41-44 ◽  
Author(s):  
Sang Kyu Park ◽  
Tae Hyuk Lee ◽  
Moon Soo Sim ◽  
Jae Soo Noh ◽  
Soo Haeng Cho ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Molten Salt ◽  
Corrosion Behavior ◽  
Structural Materials ◽  
Solute Concentration ◽  
Inert Atmosphere ◽  
Electrolytic Reduction ◽  
Corrosion Products ◽  
Alloy Formation ◽  
Lithium Molten Salt

In this study, the corrosion behavior of new Ni-based structural materials was studied for electrolytic reduction after exposure to LiCl-Li2O molten salt at 650°C for 24-216h under an oxidizing atmosphere. The new alloys with Ni, Cr, Al, Si, and Nb as the major components were melted at 1700°C under inert atmosphere. The corrosion products and fine structures of the corroded specimens were characterized by SEM, EDS, and XRD. The corrosion rate of 12wt% Cr-2wt% Si alloys and 12wt% Cr-5wt% Si alloys are below 0.3mm/year. However, the corrosion rate of 20wt% Cr-5wt% Si is 0.6mm/year. Also, the corrosion products of 12wt% Cr alloys were Cr2O3, NiCr2O4, Ni, and NiO; those of 20wt% Cr alloys were Cr2O3, LiAl2Cr3O8, and NiO. The higher corrosion rate of 20wt% Cr-5wt% Si could be the higher solute concentration which leads to an unstable alloy formation. As confirmed by the pseudo binary phase diagram of (Ni-Cr-Al-Nb)-Si, the solubility of the silicon with 20 wt% of Cr decreased to 4 wt% from 5 wt% with 12 wt% of Cr.

EIS Study of Corrosion Behavior of Hot-Dip Galvanized Steel in 5% NaCl Aqueous Solution

2011 ◽  
Vol 335-336 ◽  
pp. 779-782
Author(s):  
Shi Quan He ◽  
Hui Zhong
Keyword(s):  
Aqueous Solution ◽  
Equivalent Circuit ◽  
Corrosion Behavior ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Impedance Spectrum ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Electrochemical Impedance Spectrum

Corrosion behaviour of hot-dip galvanized steel in 5% NaCl aqueous solution was studied by electrochemical impedance spectrum (EIS) technique. The results revealed that corrosion behaviour of hot-dip galvanized steel has a great relationship with immersion time. With the increase of immersion time, corrosion products are constantly changing, and the impedance of corrosion products are different. Parameters fitted by equivalent circuit show that the impedance of corrosion products increased at first, then decreased.

Early Corrosion Behavior of Pipeline Steel Containing 1% Cr in Sea Water Environment

2015 ◽  
Vol 1120-1121 ◽  
pp. 773-778
Author(s):  
Zhen Guang Liu ◽  
Xiu Hua Gao ◽  
Lin Xiu Du ◽  
Jian Ping Li ◽  
Ping Ju Hao
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Sea Water ◽  
Pipeline Steel ◽  
Water Environment ◽  
Corrosion Products ◽  
Immersion Experiment ◽  
Three Stages ◽  
Stage 1 ◽  
Microscopic Surface

The corrosion behavior of pipeline steel containing 1%Cr is studied by using immersion experiment. The corrosion rust is characteried with macroscopic/microscopic surface morphology, corrosion kinetics and corrosion phases. The results demonstrate that the main corrosion products are lepidocrocite and goethite, Cr-rich compound consists of the inner layer. The corrosion process could be divided into three stages. At stage 1, the corrosion rate decreases fast, and the distributed corrosion products are formed. At stage 2, the granular corrosion products appear on coupons surface gradually, and a plain corrosion rate is obtained. At stage 3, a compact and dense corrosion layer attaches to coupons surface, and corrosion rate decreases mildly.

Electrochemical Investigation of Under-Deposit Corrosion Behavior for Aluminum Brass in Artificial Seawater

CORROSION ◽  
10.5006/3428 ◽  
2020 ◽  
Vol 76 (11) ◽  
pp. 1050-1063
Author(s):  
Hong Ju ◽  
Weihui Xu ◽  
Jiejing Chen ◽  
Dalei Zhang ◽  
Guomin Liu ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Electrolytic Cell ◽  
Artificial Seawater ◽  
Localized Corrosion ◽  
Effect Of Temperature ◽  
Multielectrode Arrays ◽  
Energy Dispersive Spectrometry Analysis ◽  
Spectrometry Analysis

The under-deposit corrosion behavior and mechanism of aluminum brass (HAl77-2) were investigated in artificial seawater with a custom double electrolytic cell. The experiments included linear polarization, electrochemical impedance spectroscopy, and multielectrode arrays analysis. The electrochemical results revealed a pronounced effect of temperature on the under-deposit corrosion behavior of HAl77-2. The corrosion of HAl77-2 inside the CaCO3 scale is aggravated with increasing temperature. However, the increasing frequency of the corrosion rate of HAl77-2 gradually decreased after 333 K. Moreover, in the desalination of artificial seawater, the corrosion rate of HAl77-2 in the occulated area initially increased and subsequently decreased with increasing Cl− concentration. The scanning electron microscopy and energy dispersive spectrometry analysis showed a remarkable appearance of selective localized corrosion on the surface of HAl77-2.

scholarly journals Corrosion Evaluation of Geopolymer Concrete Made with Fly Ash and Bottom Ash

2021 ◽  
Vol 13 (1) ◽  
pp. 398
Author(s):  
Priyanka Morla ◽  
Rishi Gupta ◽  
Peiman Azarsa ◽  
Ashutosh Sharma
Keyword(s):  
Fly Ash ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Bottom Ash ◽  
High Rate ◽  
Geopolymer Concrete ◽  
Cell Potential ◽  
Accelerated Corrosion ◽  
Corrosion Evaluation ◽  
Alumino Silicate

Environmental pollution caused by CO2 releasing from the production of cement is a great challenge for the construction industry and has triggered exploration into more sustainable alternatives. Geopolymer Concrete (GPC) is a potential sustainable solution that does not involve the use of cement as a binder. GPC is produced by mixing the alumino-silicate source materials such as fly-ash with alkali activators such as potassium hydroxide (KOH) and potassium silicate (K2SiO3). Unlike Ordinary Portland Concrete (OPC), the characteristics of GPC depend on the precursor materials and therefore vary for different mixes. Consequently, corrosion behavior needs to be evaluated separately for individual mixes. This has narrowed the scope of existing published work on corrosion behavior of GPC. In this study, GPC and OPC specimens were prepared and exposed to accelerated corrosion exposure. Half-cell potential and linear polarization resistance were used to evaluate the corrosion rate in GPC and OPC. Under accelerated conditions, the corrosion rate of the GPC specimens was between 10 µm/year and 20 µm/year exhibiting a moderate to high rate of corrosion. Meanwhile, the corrosion rate of the OPC specimens was between 40 µm/year and 60 µm/year indicating a very high corrosion activity. It can be concluded that GPC has a higher resistance to chloride-induced corrosion; with a low corrosion rate and lower mass loss percentage, compared to OPC.

scholarly journals A Novel Accelerated Corrosion Test for Supporting Devices in a Floating Photovoltaic System

2021 ◽  
Vol 11 (8) ◽  
pp. 3308
Author(s):  
Chun-Kuo Liu ◽  
Zhong-Ri Kong ◽  
Ming-Je Kao ◽  
Teng-Chun Wu
Keyword(s):  
Corrosion Test ◽  
Salt Spray ◽  
Protective Layer ◽  
Photovoltaic System ◽  
Galvanized Steel ◽  
Neutral Salt ◽  
Accelerated Corrosion ◽  
Accelerated Corrosion Test ◽  
Type 304

Recently, countries from around the globe have been actively developing a new solar power system, namely, the floating photovoltaic (FPV) system. FPV is advantageous in terms of efficiency and cost effectiveness; however, environmental conditions on the surface of water are harsher than on the ground, and the regulations and standards for the long-term durability of supporting devices are insufficient. As a result, this study aims to investigate the durability of supporting devices through a novel type of accelerated corrosion test, copper-accelerated acetic acid salt spray (CASS). After an eight-day CASS test, the results demonstrated that only a small area of white protective layer on the SUPERDYMA shape steel was fully corroded and rusted. Moreover, five types of screw, fastened solidly on the SUPERDYMA shape steel, namely a galvanized steel screw capped with a type 316 stainless steel (SS) nut, a type 304 SS screw, a type 410 SS screw, a chromate-passivated galvanized steel screw, and a XP zinc–tin alloy coated steel screw, achieved varying degrees of rust. In general, the corrosion degree of the eight-day CASS test was more serious than that of the 136-day neutral salt spray (NSS) test. Therefore, the CASS test is faster and more efficient for the evaluation of the durability of supporting devices.

scholarly journals Comparison of the corrosion behavior of the TiNi alloy in the coarse-grained and ultrafine-grained state

2021 ◽  
Vol 2124 (1) ◽  
pp. 012026
Author(s):  
E M Kayumova ◽  
A A Churakova ◽  
O R Latypov
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Volume Fraction ◽  
Significant Proportion ◽  
Gravimetric Method ◽  
Corrosion Products ◽  
Coarse Grained ◽  
Tini Alloy ◽  
Ultrafine Grained ◽  
Coarse Grained State

Abstract This article studies the corrosion behavior of the TiNi alloy in the coarse-grained and ultrafine-grained states. The study of the influence of the initial microstructure on the corrosion behavior of the TiNi alloy was carried out by the gravimetric method in the NaCl and H2SO4 solution for a month. Studies was shown that as a result of the action of a corrosive medium from a sample in a coarse-grained state, it undergoes greater destruction, pitting corrosion was observed, at the same time, in an ultrafine-grained sample only traces of corrosion products are observed on the surface of the samples. Investigations with an inverted light microscope in a dark field made it possible to observe corrosion products and determine their volume fraction. Evaluation of the corrosion rate showed that in the coarse-grained state it is 126 times higher than the corrosion rate in the ultrafine-grained state. Analysis of X-ray phase analysis showed that in the coarse-grained state after corrosion tests, a significant proportion of the TiNiH1.4 phase is observed, while in the ultrafine-grained state all phases correspond only to the TiNi phases. The TiNi alloy contains an Ti2Ni phase enriched Ti both in the coarse-grained state and in the ultrafine-grained state. Moreover, in a coarse-grained state, its share is 2 times higher.

scholarly journals Influence of calcium cations on the corrosion behavior of hot-dip galvanized steel in model concrete pore solutions

2019 ◽  
Vol 63 (1) ◽  
pp. 23-36 ◽  
Author(s):  
P. Pokorný ◽  
M. Kouřil
Keyword(s):  
Confocal Microscopy ◽  
Phase Analysis ◽  
Surface Analysis ◽  
Corrosion Behavior ◽  
Polarization Resistance ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Resistance Surface ◽  
Calcium Cations ◽  
Xrd Phase Analysis

Abstract In this paper, the influence of calcium cations on the corrosion behavior of hot-dip galvanized steel in model concrete pore solutions is evaluated by means of conventional electrochemical methods (measurement of free corosion potencial and polarization resistance), surface analysis methods (optical and confocal microscopy) and XRD phase analysis of precipitated corrosion products. The results of these experiments confirm the conclusions of the current work on a similar topic, i.e. the crystalline calcium based corrosion products Ca[Zn(OH)3]2·2H2O are not able passivate effectively surface of hot-dip galvanized steel in model of concrete pore solutions (pH 12.6; 13.0). If passivation occurs, a mixed Ca[Zn(OH)3]2·2H2O, ZnO and Zn(OH)2 is involved.

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