Corrosion Behavior of Ceramic Dispersion Strengthened High-Cr Stainless Steel

2008 ◽  
Vol 135 ◽  
pp. 127-130
Author(s):  
Gyoung Ja Lee ◽  
Sang Hoon Lee ◽  
Sung Mo Hong ◽  
Byung Sun Han ◽  
Jin Ju Park ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Potentiodynamic Polarization ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
High Energy ◽  
Polarization Curves ◽  
Pitting Potential ◽  
Potentiodynamic Polarization Curves ◽  
High Energy Ball Mill ◽  
Energy Ball

In the present work, corrosion characteristics of ceramic dispersion strengthened (CDS) high-Cr stainless steel (SS) has been investigated. For the preparation of CDS SS with uniformly distributed reinforcements, TiC particles were mechanically activated with Cu powder by using high-energy ball mill machine, and then Cu-coated TiC particles were mixed with molten SS. Potentiodynamic polarization curves were experimentally measured on unmodified SS and CDS SS in 0.05 M NaCl solution. The values of corrosion potential Ecorr, corrosion current io, pitting potential Epit and polarization resistance Rp were quantitatively determined from the measured potentiodynamic polarization curves. From the result, it is concluded that CDS SS exhibits higher corrosion resistivity than unmodified SS.

Studies on Corrosion Behavior of S-165 and HP Supermartensitic Stainless Steels in Cl- Environment

2011 ◽  
Vol 695 ◽  
pp. 425-428
Author(s):  
Duo Wang ◽  
De Ning Zou ◽  
Chang Bin Tang ◽  
Kun Wu ◽  
Huan Liu
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Stainless Steels ◽  
Potentiodynamic Polarization ◽  
Electrochemical Impedance ◽  
Polarization Curves ◽  
Chemical Compositions ◽  
Pitting Potential ◽  
Potentiodynamic Polarization Curves

Supermartensitic stainless steel grades are widely used in oil and gas industries to substitute duplex and super duplex stainless steels these years. In this paper the corrosion behavior of supermartensitic stainless steels with different chemical compositions, S-165 and HP, was investigated in Cl-environment. All the samples were treated by quenching at 1000 °C followed by tempering at 630 °C for 2h. After heat treatment, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) were determined on both kinds of samples. Polarization curves shows that the metastable pitting nucleuses were formed in passive area and the Cr content is the most important factor leading to the differences of pitting potential. The potentiodynamic polarization curves were conducted at various NaCl contents (5000, 15000 and 35000 ppm) and emphasized the need to account for the Cl-sensitivity of samples under corrosion environment. The results show that, the pitting potential decrease with the increase of chloride contents. The behavior of passive film was analyzed by electrochemical impedance spectroscopy.

Effect of Cl- Concentration on Pitting Corrosion Property of Maraging Hardened Stainless Steel Based on Pourbaix Diagram

2018 ◽  
Vol 940 ◽  
pp. 59-64 ◽  
Author(s):  
Xin Zhang ◽  
De Ning Zou ◽  
Yu Qing Zhou ◽  
Xuan Na ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Pitting Corrosion ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Corrosion Property ◽  
Ion Concentration ◽  
Pitting Potential ◽  
Pitting Corrosion Resistance ◽  
The Matrix ◽  
Simulation Results

The corrosion behavior of maraging hardened stainless steel (MHSS) in different Cl-medium was investigated by thermodynamics simulation and electrochemical experiments. The simulation results show that the thermodynamic stability zone decreases with the increase of the concentration of Cl-. Some of chromium transformed into Cr(OH)2+and adsorbed on the surface of stainless steel, and others generated Cr2O3protecting the matrix. Mo reacted with O2to form MoO42-adsorbed on the surface of the material, which inhibited the destruction of Cl-. The electrochemical experiments indicate that the concentration of Cl-is in the range of 2%-7%. The pitting potential and self-corrosion potential of MHSS decreased linearly with the increase of ion concentration, and the pitting corrosion resistance of MHSS decreased. When the self-corrosion current increases from 1.9888 μA to 2.6524 μA, the corrosion tendency of the material enhances.

Correlation between AC magnetic susceptibility and pitting behaviour of sigma-phase containing duplex stainless steel

2015 ◽  
Vol 62 (6) ◽  
pp. 371-378 ◽  
Author(s):  
Kin Ho Lo ◽  
Chi Tat Kwok ◽  
Hong Cheng Kuan ◽  
Weng Kin Chan ◽  
Wenji Ai
Keyword(s):  
Stainless Steel ◽  
Magnetic Susceptibility ◽  
Duplex Stainless Steel ◽  
Sigma Phase ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Ac Magnetic Susceptibility ◽  
Pitting Potential ◽  
Content Type ◽  
Passive Current

Purpose – The purpose of this paper is to characterize the pitting behaviour of sigma-phase-containing duplex stainless steel and investigate the correlation between magnetic susceptibility and pitting potentials. Design/methodology/approach – Use an alternating current (AC) magnetic susceptometer to trace the change in magnetic susceptibility associated with sigma phase formation and systematic study of the effects of sigma precipitation on pitting parameters as obtained using the anodic potentiodynamic polarization test. Findings – The precipitation of sigma phase impairs the general and pitting corrosion resistance of duplex stainless steel. The pitting potential, the corrosion potential and the AC magnetic susceptibility have good correlations. Unlike the pitting potential and the corrosion potential, the passive current and the corrosion current do not seem to possess any trend with annealing time. Originality/value – The correlation between AC magnetic susceptibility and pitting parameters has not been reported in the literature before.

Improvement of Corrosion Resistance of Stainless Steel by ZrO2-SiO2 Sol-Gel Coatings

2006 ◽  
Vol 510-511 ◽  
pp. 442-445 ◽  
Author(s):  
Dae Yong Shin ◽  
Kyung Nam Kim ◽  
In-Tak Nam ◽  
Sang Mok Han
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Potentiodynamic Polarization ◽  
Sol Gel ◽  
Comparative Test ◽  
Polarization Curves ◽  
Potentiodynamic Polarization Curves ◽  
Electrochemical Parameters ◽  
Sol Gel Process ◽  
316 L Stainless Steel

ZrO2-SiO2 coatings deposited on 316 L stainless steel were prepared to protect chemically the substrates by sol-gel process using Zr(OC3H7 n)4/Si(OC2H5)4 as precursors. The influence of the ZrO2-SiO2 coatings on the corrosion resistance of the 316 L stainless steel was evaluated with the potentiodynamic polarization curves in deareated 15% H2SO4 solutions at 25, 40 and 50 °C . Comparative test was performed on uncoated one. The values of the electrochemical parameters explain how. ZrO2-SiO2 films increase the resistance of stainless steel against corrosion.

The use of polymeric milling media in the reduction of contamination during mechanical attrition

2002 ◽  
Vol 17 (12) ◽  
pp. 2997-2999 ◽  
Author(s):  
Claudio L. De Castro ◽  
Brian S. Mitchell
Keyword(s):  
Stainless Steel ◽  
Thermogravimetric Analysis ◽  
Crystallite Size ◽  
Ball Mill ◽  
High Energy ◽  
Organic Contamination ◽  
X Ray ◽  
Mechanical Attrition ◽  
High Energy Ball Mill ◽  
Energy Ball

Aluminum samples were milled in a high-energy ball mill at times ranging from 10 to 500 min in stainless vial/media and nylon vial/media. The crystallite size of aluminum milled in the stainless steel setup reached a plateau at 25 nm around 100 min, whereas the crystallite size of aluminum milled in the nylon setup reached the same plateau at 500 min. Contamination studies were conducted using x-ray fluorescence, hydrogen–carbon–nitrogen analysis, and thermogravimetric analysis. Although organic contamination due to the nylon milling media was high at 12 wt% when milled for 500 min, it is shown that the contaminant could be easily removed by thermal treatment.

scholarly journals Defect-induced B4C electrodes for high energy density supercapacitor devices

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Özge Balcı ◽  
Merve Buldu ◽  
Ameen Uddin Ammar ◽  
Kamil Kiraz ◽  
Mehmet Somer ◽  
...  
Keyword(s):  
Active Carbon ◽  
High Performance ◽  
Carbon Sources ◽  
High Energy ◽  
High Energy Density ◽  
Synthesis Conditions ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
G Ratio ◽  
Energy And Power Density

AbstractBoron carbide powders were synthesized by mechanically activated annealing process using anhydrous boron oxide (B2O3) and varying carbon (C) sources such as graphite and activated carbon: The precursors were mechanically activated for different times in a high energy ball mill and reacted in an induction furnace. According to the Raman analyses of the carbon sources, the I(D)/I(G) ratio increased from ~ 0.25 to ~ 0.99, as the carbon material changed from graphite to active carbon, indicating the highly defected and disordered structure of active carbon. Complementary advanced EPR analysis of defect centers in B4C revealed that the intrinsic defects play a major role in the electrochemical performance of the supercapacitor device once they have an electrode component made of bare B4C. Depending on the starting material and synthesis conditions the conductivity, energy, and power density, as well as capacity, can be controlled hence high-performance supercapacitor devices can be produced.

A Study of Exchange-Coupling Effect on Nd2Fe14B / α-Fe Forming Core/Shell Shape

2007 ◽  
Vol 119 ◽  
pp. 147-150 ◽  
Author(s):  
Chang Woo Kim ◽  
Young Hwan Kim ◽  
Don Keun Lee ◽  
In Chul Jeong ◽  
Hae Woong Kwon ◽  
...  
Keyword(s):  
Exchange Coupling ◽  
Ball Mill ◽  
Coupling Effect ◽  
Chemical Reduction ◽  
High Energy ◽  
Shell Shape ◽  
Core Shell ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Mill Process

We report the core/shell type as the interesting one of the various techniques to prepare exchange-coupled permanent magnet. In this study, the exchange-coupled Nd2Fe14B/α-Fe was prepared by high energy ball mill process and chemical reduction. Nd15Fe77B8 powder prepared by high energy ball mill process was coated with α-Fe nanoparticle by chemical reduction. α-Fe nanoparticle on the ball milled Nd15Fe77B8 was synthesized by chemical reduction with borohydride as a reducing agent in aqueous solution. After annealing, Nd2Fe14B/α-Fe forming core/shell shape has exchange-coupling effect and was identified by using XRD, FE-SEM, VSM, TMA and EDX.

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