scholarly journals Enhancing Corrosion Resistance and Hardness Properties of Carbon Steel through Modification of Microstructure

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2404 ◽  
Author(s):  
Wilson Handoko ◽  
Farshid Pahlevani ◽  
Veena Sahajwalla
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Carbon Steel ◽  
Confocal Microscopy ◽  
Laser Scanning ◽  
Volume Fraction ◽  
Mechanical Test ◽  
Industrial Applications ◽  
Primary Role ◽  
Phase Volume Fraction

Steel has played a primary role as structural and fabricating materials in various industrial applications—including the construction sector. One of the most important properties of steel that required a constant improvement is corrosion resistance specifically in corrosive environment. For this purpose, various approaches have been conducted through different heat treatment parameters to compare its microstructural engineering on chemical and mechanical properties. In this paper, correlation of different microstructure on corrosion resistance and hardness properties have been investigated. Three different heat treatment cycle have been applied on carbon steel with same composition to prepare dual-structure (DS) steel that consisted of ferrite/pearlite and triple-structure (TS) with ferrite/pearlite/bainite and ferrite/bainite/martensite. Phase transformation during heat treatment process was analyzed through in-situ ultra-high temperature confocal microscopy. Effect of corrosion behavior on these steels was investigated by Tafel plot, Scanning Electron Microscopy (SEM), 3D laser scanning confocal microscopy (3DLSCM), and calculation of phase volume fraction by ImageJ. Mechanical test was conducted by Vickers hardness test. It has been found that TS steels that have improvement in corrosion resistance accounted around 5.31% and hardness value for up to 27.34% more than DS steel, because of tertiary phase—bainite/martensite. This corrosion rate was reduced due to decreased numbers of pit growth and lower level of boundary corrosion as bainite/martensite phases emerged.

scholarly journals Effect of Heat Treatment on the Microstructure and Corrosion Resistance of Stainless/Carbon Steel Bimetal Plate

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Hao Li ◽  
Liyuan Zhang ◽  
Boyang Zhang ◽  
Qingdong Zhang
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
Carbon Steel ◽  
Carbon Content ◽  
Carbon Diffusion ◽  
Annealing Process ◽  
Stainless Steel Surface ◽  
Surface Corrosion ◽  
Annealing Conditions

In order to research the effect of heat treatment on the microstructure and corrosion resistance of stainless/carbon steel bimetal plate, the annealing process at 700°C with different times was carried out for stainless/carbon steel bimetal plate. Because the carbon content of carbon steel was higher than that of stainless steel, the carbon would diffuse from carbon steel to stainless steel in the bimetal plate during the annealing process. The carbon diffusion would cause the thickness of the decarburized layer in carbon steel and the carbon content of stainless steel to increase. The carbon diffusion would be ongoing with the annealing process until the carbon content of stainless steel reached 0.08%. The higher carbon content could help in the formation of more chromium-depleted regions in the stainless steel surface, causing the stainless steel in the bimetal plate to have a poorer surface corrosion resistance than that of stainless steel under the same annealing conditions.

Effect of Thermal Cycle on Microstructure and Corrosion Behavior of Duplex Stainless Steel SAF 2205 Electron Beam Welded Joint

2018 ◽  
Vol 786 ◽  
pp. 119-127
Author(s):  
Sameh M. Khafagy ◽  
Morsy Amin Morsy ◽  
H.M. El Sherbini ◽  
Y.F. Barakat
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Duplex Stainless Steel ◽  
Thermal Cycle ◽  
Welded Joint ◽  
Volume Fraction ◽  
Holding Time ◽  
Σ Phase ◽  
Phase Volume Fraction ◽  
Saf 2205

It is known that heat treatment (HT) highly affects the properties of base metal (BM) and fusion zones (FZ) of duplex stainless steel (DSS). In fact, it may give unwanted structure changes. Duplex stainless steels SAF 2205 welded joint was subjected to thermal cycle at temperature of 850◦C at holding times 1, 3, 5 and 7 hours. The influence of heating cycles and concentration of corrosive medium on the corrosion properties and microstructure of 2205 alloy was the objective of this work. It was found that process led to noticeable decrease in the corrosion resistance of BM and FZ specimens; moreover the decrease was large in BM than FZ. It was also found that sigma phase (σ) precipitated in the different zones of the structure. σ phase volume fraction was found to increase with increasing the holding time of HT, and its increase is larger in BM. Corrosion resistance was found to be oppositely related to σ phase formation. Secondary austenite phase (γ2) was also precipitated and its volume fraction in FZ was found to increase with increasing the holding time of HT and decreased in BM.

Influences of Zinc Content and Solution Heat Treatment on Microstructure and Corrosion Behavior of Mg-Zn Binary Alloys

CORROSION ◽  
10.5006/3672 ◽  
2020 ◽  
Author(s):  
Dinh Pham ◽  
Sachiko Hiromoto ◽  
Equo Kobayashi
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Volume Fraction ◽  
Galvanic Corrosion ◽  
Zinc Content ◽  
Eutectic Cell ◽  
Zn Content ◽  
Cast Alloys

The influences of Zn content and heat treatment on microstructure and corrosion behavior of Mg-xZn (x=1, 3, 5 and 7 wt.%) alloys were studied. (α-Mg + MgZn) eutectic cells and Zn-segregated regions were formed in the as-cast alloys. The Zn-rich phases acted as micro-cathodes in galvanic corrosion. Volume fraction of the Zn-rich phases increased with Zn content of the as-cast alloys, leading to a decrease in corrosion resistance. The corrosion rate of the as-cast alloys increased by 4 times with an increase of the volume fraction of eutectic cell from 0.07 vol.% of Mg-1Zn alloy to 2.18 vol.% of Mg-5Zn alloy. The corrosion rate of Mg-7Zn alloy with 2.87 vol% eutectic cells was 2 times higher than that of Mg-5Zn alloy. The Zn-rich phases dissolved by the T4 treatment and only the T4-treated Mg-7Zn alloy obviously showed eutectic cells of 1.73 vol.%. The polarization resistance (Rp) of the T4-treated Mg-1, 3 and 5Zn alloys was 2-10 times higher than that of the as-cast alloys. The T4-treated Mg-7Zn showed similar Rp to the as-cast Mg-5Zn alloy. Consequently, the volume fraction of Zn-rich phases dominated the corrosion resistance of Mg-xZn alloys.

An investigation on thermodynamics and kinetics of η phase formation in Nb-modified iron-nickel base A286 superalloy

2020 ◽  
Vol 118 (1) ◽  
pp. 105
Author(s):  
Reza Soleimani Gilakjani ◽  
Seyed Hossein Razavi ◽  
Masoumeh Seifollahi
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Phase Formation ◽  
Volume Fraction ◽  
Treatment Time ◽  
Diffusion Activation Energy ◽  
Phase Volume Fraction ◽  
Titanium Nickel ◽  
Nickel Base ◽  
Microstructural Studies

In this study, precipitation of η phase (Ni3Ti) in conventional and Nb-modified (Nb-A286) A286 superalloys was evaluated at different aging times and temperatures. The TTP curve of the η phase formation was plotted using thermodynamic analyses, kinetics and microstructural studies. Depending on temperature and heat treatment, the η phase precipitated at the grain boundaries or twin sites, as a result of the γ′ phase or matrix austenite transformation. Heat treatment of conventional A286 superalloy and Nb-A286 was performed within a temperature range of 650 to 900 °C for 2 to 30 h. The η phase transformation was evaluated by scanning electron microscope (SEM) which is equipped to energy dispersive X-ray spectroscopy (EDS) and optical microscopy (OM). In the analyses based on thermodynamic calculations, the interaction of the Gibbs free energy of η phase formation and the diffusion activation energy of the elements, especially titanium and niobium, was considered. The microstructural studies showed that increasing the heat treatment time results in increasing the volume fraction of the η phase. By increasing the aging temperature to 840 and 860 °C for conventional A286 superalloy and Nb-A286 superalloy, respectively, the η phase volume fraction increased, however, further increase led to volume fraction decrease. The results of the thermodynamic analyses showed the tip of the TTP diagrams at temperatures of 860 and 820 °C for the A286 and Nb-A286 alloys, respectively. Investigation of kinetics calculations showed that η phase transformation depends on the diffusion of titanium, nickel, and niobium.

Phosphate Coatings Suitable for Personal Protective Equipment

2021 ◽  
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Phosphoric Acid ◽  
Personal Protective Equipment ◽  
Applied Research ◽  
Industrial Applications ◽  
Protective Equipment ◽  
Mechanical Shocks ◽  
Phosphate Coatings ◽  
Steel Equipment

Phosphate coatings can improve the corrosion resistance of carbon steel equipment such as carabiners. The specific porosity of the phosphate layer allows the deposition of an elastomer-based paint for absorbing mechanical shocks. The book is relevant for fundamental and applied research in the field of protective phosphate layers and their industrial applications. It also describes how to design and develop phosphating solutions that differ in the type and concentration of metal ions dissolved in phosphoric acid.

Modelling the Heat Treatment of Sintered SmCo5 Magnets

2006 ◽  
Vol 530-531 ◽  
pp. 152-157 ◽  
Author(s):  
Marcos Flavio de Campos ◽  
José Adilson de Castro ◽  
Paulo Rangel Rios
Keyword(s):  
Heat Treatment ◽  
Strong Influence ◽  
Volume Fraction ◽  
Precipitate Size ◽  
Second Law ◽  
Phase Volume ◽  
Phase Volume Fraction ◽  
Intrinsic Coercivity ◽  
Order Of Magnitude ◽  
Volume Method

The processing of SmCo5 sintered magnets involves a post-sintering heat treatment, where the intrinsic coercivity of the magnets may increase more than one order of magnitude. Variables of the heat treatment like time, temperature and cooling rate have strong influence on coercivity. We describe a method for modeling the heat treatment, which includes microstructural features as precipitate size and 2nd phase volume fraction. The numerical solution was obtained using the Finite Volume Method to solve Fick´s second law. Experimental data like the diffusion coefficient of Sm into SmCo5 phase and the Sm-Co phase Diagram are used for the modeling.

Effects of Heat Treatment on Microstructure and Properties of AZ91D Magnesium Alloy

2013 ◽  
Vol 575-576 ◽  
pp. 410-413
Author(s):  
Ming Wu ◽  
Fang Long ◽  
Hao Ran Geng ◽  
Fang Yang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Test ◽  
Artificial Aging ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Second Phase ◽  
Az91d Alloy ◽  
Az91d Magnesium Alloy ◽  
Heat Treated

The microstructure, hardness and corrosion resistance of AZ91D alloy were investigated under different solution treatments and artificial aging conditions.When ascast AZ91D alloy was heat treated at 415°C by solution treatmentfor 12 h and artificially aged at 200°C, the volume fraction of precipitates increased with the aging time up to 10 h.When ascast AZ91D alloy was treated at 430°C by solution treatment for 12 h and artificially aged at 200°C for 10h, the volume fraction of precipitates reached a peak value.The results of the corrosion test showed that a high corrosion resisting of the second phase precipitates was beneficial to improving the strength and hardness. Solution treatment at 445°C temperature for 12 h destroied the consecutiveness of β-Mg17Al12 phases.

scholarly journals Enhancing Corrosion Resistance of High-Carbon Steel by Formation of Surface Layers Using Wastes as Input

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 902 ◽  
Author(s):  
Handoko ◽  
Pahlevani ◽  
Sahajwalla
Keyword(s):  
Corrosion Resistance ◽  
Laser Scanning ◽  
Volume Fraction ◽  
High Carbon Steel ◽  
Microstructural Analysis ◽  
Electrochemical Corrosion ◽  
Single Step ◽  
Carbon Steels ◽  
Chemical Mapping ◽  
High Carbon

Series of super-hard ceramic layers have been successfully developed on high carbon steels, with a significant improvement of corrosion resistance and hardness, without changing the original properties, which were derived from mixtures of slag (electric arc furnace), waste glass (bottles), and automotive shredder residue (ASR) plastics (polypropylene) via the single step surface modification technique. Microstructural analysis by laser scanning confocal microscopy (LSCM), crystallography analysis by X-ray diffraction (XRD), micro-level chemical analysis by scanning electron microscopy and energy dispersive spectroscopy (SEM and EDS), and depth profile surface analysis with three-dimensional chemical mapping by time-of-flight secondary ion mass spectrometry (TOF-SIMS), followed by electrochemical corrosion test by the Tafel method and hardness test—Vickers hardness measurement. Three areas have been classified, modified surface, interface, and main substrate areas as the synthesis of ceramic layers into surface of the steels that thermodynamically formed during the heat treatment process. Chemical composition analyses have revealed that generated layers consisting of chromium (Cr)- and magnesium (Mg)-based compound have shown an improved corrosion resistance to 52% and hardness to 70% without modifying the initial volume fraction of constituent phases–martensite and retained austenite. These findings have substantially highlighted to the potential use of waste-integrated inputs as raw materials for production in cost-effective way, concurrently decreasing the demand on new resource for coating, alleviating the disadvantageous impact to the environment from waste disposal in landfills.

A One-Step Pack Cementation Method for Preparing AlN/Aluminizing Coating with Good Corrosion Resistance

2019 ◽  
Vol 295 ◽  
pp. 3-8
Author(s):  
Xiao Yan Wang ◽  
Jiao Jiao Du ◽  
Zhong Wei Ma
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Low Cost ◽  
Electrochemical Measurement ◽  
Industrial Applications ◽  
Pack Cementation ◽  
Diffraction Spectrum ◽  
X Ray ◽  
Good Corrosion Resistance ◽  
One Step

AlN/aluminizing coating with good corrosion resistance on carbon steel was prepared by one-step powder pack method. The phase compositions were analyzed by X-Ray diffraction spectrum (XRD). The cross-sections were investigated by scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS). According the analysis above, the appropriate powder formula and technological parameter were determined: 40 wt.% Al + 50 wt.%Al2O3 + 5 wt.% NH4Cl + 5 wt.%CeO2, heating from 800 °C and maintaining at 900 °C for 6 hours. The corrosion resistance of specimen with AlN/aluminizing coating were measured by electrochemical test. The electrochemical measurement suggested that the corrosion resistance property of carbon steel was remarkably improved by fabricating AlN/aluminizing film. The process of pack cementation method in this fabrication is very simple, low-cost and facile, which opens a promising and effective path for industrial applications for AlN/aluminizing coating on various metallic materials.

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