scholarly journals Effect of Corrosion Characteristics on Long-Term Aging of Austenitic 304 Steel

2019 ◽  
Vol 9 (24) ◽  
pp. 5557
Author(s):  
Chaeeul Huh ◽  
Seongbin An ◽  
Minsuk Kim ◽  
Chungseok Kim
Keyword(s):  
Aging Time ◽  
Current Density ◽  
Corrosion Potential ◽  
Electrochemical Corrosion ◽  
Optical Microscope ◽  
M23c6 Carbide ◽  
Aisi 304 ◽  
Σ Phase ◽  
Aisi 304 Steel

The objective of this study is to investigate the effect of long-term aging on electrochemical corrosion characteristics of austenitic AISI 304 steel. AISI 304 steel was subjected to aging treatment for an extended period at 700 °C up to a maximum of 10,000 h. The variation in the microstructure of aged specimens was observed with an optical microscope (OM) and a scanning electron microscope (SEM). The electrochemical polarization test was conducted to obtain the corrosion current density (Icorr) and corrosion potential (Ecorr). The metastable intermetallic M23C6 carbides generated in the vicinity of γ/γ grain boundaries and coarsened with aging time. The δ-ferrite island decomposed into σ-phase and M23C6 carbide with an aging time increase. As the aging time increased, the current density increased, but the corrosion potential of the austenitized specimen exhibited a minimum value of 0.04 μA/cm2. The highest pitting resistance exhibited at the austenitized specimen due to the absence of carbides. Consequently, the corrosion resistance of austenitic AISI 304 steel decreases with long-term aging time. The microstructural analyses well support this result.

Protective Insulated Coating for IGSCC Mitigation in BWRs

2004 ◽  
Author(s):  
Young-Jin Kim
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Water Chemistry ◽  
Corrosion Potential ◽  
Electrochemical Corrosion ◽  
304 Stainless Steel ◽  
High Temperature Water ◽  
Coating Methods ◽  
Temperature Water

A protective insulated coating (PIC) on 304 stainless steel (SS) surfaces as an IGSCC mitigation method was developed and investigated in high temperature water under various water chemistry conditions by measuring the electrochemical corrosion potential (ECP) and flow-assisted corrosion (FAC) rate. The ECP results clearly demonstrate that the PIC layer restricted oxidant transport to the metal surface, and the ECP remained at <−230 mV (SHE) in 288°C containing high oxygen (O2) and no hydrogen (H2). In this paper, long term durability of PIC layer prepared by various coating methods will be discussed.

Electrochemical corrosion study of Pb-free solders

2006 ◽  
Vol 21 (1) ◽  
pp. 62-70 ◽  
Author(s):  
B.Y. Wu ◽  
Y.C. Chan ◽  
M.O. Alam ◽  
W. Jillek
Keyword(s):  
Acid Solution ◽  
Corrosion Behavior ◽  
Current Density ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Corrosion Properties ◽  
Linear Polarization Resistance ◽  
Eis Measurements

This paper presents an investigation on the corrosion behavior of five solders by means of polarization and electrochemical impedance spectroscopy (EIS) measurements. The Sn–9Zn and Sn–8Zn–3Bi solder, in comparison with the Sn–3.5Ag–0.5Cu and Sn–3.5Ag–0.5Cu–9In solder, were tested in 3.5 wt% NaCl solution and 0.1 wt% adipic acid solution, respectively. The Sn–37Pb solder was for reference in this work. The polarization curves indicated that the Sn–9Zn and Sn–8Zn–3Bi solder showed the worst corrosion resistance both in the salt and acid solutions, in terms of corrosion-current density, corrosion potential, linear polarization resistance, and passivation-current density. Meanwhile, the Sn–3.5Ag–0.5Cu solder remained the best corrosion characteristics in both solutions. It was found that due to microstructure alteration, Bi additive to the Sn–9Zn solder improved the corrosion behavior in the salt solution, whereas decreased that in the acid solution. However, the additive of In degraded the Sn–3.5Ag–0.5Cu solder in both solutions. The EIS results agreed well with the noble sequence of the five solders subjected to the two solutions with polarization. The equivalent circuits were also determined. Nevertheless, the four Pb-free solders exhibited acceptable corrosion properties since there was not much difference of key corrosion parameters between them and the Sn–37Pb solder.

scholarly journals Galvanic Corrosion of SA106 Gr.B Coupled with Magnetite in Alkaline Solution at Various Temperatures

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 628
Author(s):  
Soon-Hyeok Jeon ◽  
Geun Song ◽  
Sang Kim ◽  
Do Hur
Keyword(s):  
Current Density ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Galvanic Corrosion ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Area Ratio ◽  
Manganese Steel ◽  
Effect Of Temperature ◽  
Reductive Dissolution

The effect of temperature on the galvanic corrosion behavior of SA106 Gr.B carbon-manganese steel was studied in an alkaline aqueous solution at various temperatures (30, 60, and 90 °C) via electrochemical corrosion tests. At all temperatures studied, carbon-manganese steel acted as the anode of the galvanic cell composed of carbon-manganese steel and magnetite because the corrosion potential of carbon-manganese steel was significantly lower than that of magnetite. The corrosion current density of carbon-manganese steel significantly increased due to the galvanic effect irrespective of temperature used in this study. With the increase in temperature, the extent of the galvanic effect on the corrosion current density of carbon-manganese steel and reductive dissolution of magnetite gradually increased. When the area ratio of magnetite to carbon-manganese steel increased, the corrosion rate of the carbon-manganese steel in contact with magnetite further increased.

Long-Term Evolution of Corrosion Potential of Carbon Steel in Alkaline Radioactive Waste Environments

CORROSION ◽  
10.5006/2979 ◽  
2019 ◽  
Vol 75 (1) ◽  
pp. 106-119 ◽  
Author(s):  
K.J. Evans ◽  
N. Sridhar ◽  
B.C. Rollins ◽  
S. Chawla ◽  
J.A. Beavers ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Current Density ◽  
Corrosion Potential ◽  
Nitrite Reduction ◽  
Localized Corrosion ◽  
Small Contribution ◽  
Passive Current Density ◽  
Passive Current ◽  
Over Time

The long-term shifts of corrosion potential are important in predicting the likelihood of localized corrosion and stress corrosion cracking (SCC) of carbon steel used for storing radioactive wastes in underground storage tanks. Although considerable work has been done in understanding the passivity and corrosion potential of steel in various electrolytes, an important aspect of the current work is in assessing the effects of multiyear exposures of steel in waste simulants and their effects on corrosion potential. It is shown that SCC susceptibility of steel in nitrate increases at the long-term corrosion potential in solutions without organics (either by applying that potential or letting the corrosion potential increase over time). The long-term increase in corrosion potential results principally from a decrease in the passive current density with time of exposure. The present work shows that such a reduction in passive current density is accompanied by changes in the semi-conductive properties of the passive film, which itself may be a result of changes in stoichiometry of the film over time. Nitrite reduction is the most likely cathodic reaction with a small contribution from oxygen reduction. However, the presence of organic species in the environment can result in additional anodic reactions that may decrease the corrosion potential.

Microstructures Evolution of a Ni-Base Superalloy after Long-Term Aging at 750°C

2007 ◽  
Vol 561-565 ◽  
pp. 387-390
Author(s):  
Tong Cui ◽  
Ji Jie Wang ◽  
Li Qing Chen ◽  
Guang Pu Zhao ◽  
Hong Cai Yang
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Aging Time ◽  
Aging Process ◽  
M23c6 Carbide ◽  
New Type ◽  
Base Superalloy

The microstructures evolution of a new type Ni-base superalloy has been investigated after long-term aging at 750°C for 2000h. The results indicate that TCP, a harmful phase greatly affects the mechanical properties of the alloy, is un-precipitated in the aging process. γ´ phase is precipitated in two kinds of sizes during long-term aging. The shape of larger one is transit from spherical to cubic with prolonging of aging time. The M23C6 carbide formed mainly by Cr, and other elements such as Al, Ti, Co and Mo is also precipitated in both γ matrix and grain boundaries, and the quantities of the carbide increase gradually with the increasing of aging time.

Optimization of Cutting Parameters Considering Surface Roughness When Milling AISI 304 Steel Using Coated Wc-Co and Tialn / Wc-Co Coated

2019 ◽  
Author(s):  
Murilo Pereira Lopes ◽  
Jose Rubens Gonçalves Carneiro ◽  
Gilmar Cordeiro da Silva ◽  
Carlos Eduardo Santos ◽  
Ítalo Bruno dos Santos
Keyword(s):  
Surface Roughness ◽  
Cutting Parameters ◽  
Aisi 304 ◽  
Aisi 304 Steel ◽  
Optimization Of Cutting Parameters

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

scholarly journals Study on the Influence of the Ball Material on Abrasive Particles’ Dynamics in Ball-Cratering Thin Coatings Wear Tests

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 668
Author(s):  
Gustavo Pinto ◽  
Andresa Baptista ◽  
Francisco Silva ◽  
Jacobo Porteiro ◽  
José Míguez ◽  
...  
Keyword(s):  
Aisi 304 ◽  
Thin Coatings ◽  
Iron And Steel ◽  
Test Configuration ◽  
Abrasive Particles ◽  
Aisi 52100 ◽  
Aisi 304 Steel ◽  
Aisi 52100 Steel ◽  
Steel Balls ◽  
Particles Dynamics

Micro-abrasion remains a test configuration hugely used, mainly for thin coatings. Several studies have been carried out investigating the parameters around this configuration. Recently, a new study was launched studying the behavior of different ball materials in abrasive particles’ dynamics in the contact area. This study intends to extend that study, investigating new ball materials never used so far in this test configuration. Thus, commercial balls of American Iron and Steel Institute (AISI) 52100 steel, Stainless Steel (SS) (AISI) 304 steel and Polytetrafluoroethylene (PTFE) were used under different test conditions and abrasive particles, using always the same coating for reference. Craters generated on the coated samples’ surface and tracks on the balls’ surface were carefully observed by Scanning Electron Microscopy (SEM) and 3D microscopy in order to understand the abrasive particles’ dynamics. As a softer material, more abrasive particles were entrapped on the PTFE ball’s surface, generating grooving wear on the samples. SS AISI 304 balls, being softer than the abrasive particles (diamond), also allowed particle entrapment, originating from grooving wear. AISI 52100 steel balls presented particle dynamics that are already known. Thus, this study extends the knowledge already existing, allowing to better select the ball material to be used in ball-cratering tests.

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