Microstructural change and corrosion variation of SAPH440 steel induced by pre-deformation

2019 ◽  
Vol 9 (6) ◽  
pp. 610-615
Author(s):  
Shuo Weng ◽  
Hongchang Cai ◽  
Lihui Zhao ◽  
Songlin Zheng
Keyword(s):  
Electron Microscopy ◽  
Tensile Elongation ◽  
Corrosion Current ◽  
Open Circuit ◽  
Corrosive Solution ◽  
Microstructure Observation ◽  
Transmission Electron ◽  
Weight Loss Method ◽  
Corrosion Susceptibility ◽  
Loss Method

The influence of microstructural variation on corrosion of SAPH440 steel induced by pre-deformation has been investigated in the corrosive solution. The microstructure observation was carried out by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The corrosion was characterized by weight loss method (WLM), open circuit potential (OCP) and potentiodynamic polarization curve (PPC) measurements. The results show that compared to the as-received specimens, the corrosion potential moves to the negative direction and corrosion current density increases after pre-deformation. The corrosion susceptibility is enhanced by the pre-deformation behavior, which is attributed to the increase in dislocation density with the increasing tensile elongation.

The Influence of Different Gas Welding Flame on Corrosion Behavior of the Carbon Steel’s Heat Affected Zone in Seawater

2015 ◽  
Vol 1120-1121 ◽  
pp. 1059-1063
Author(s):  
Cai Xiang Gu ◽  
Guang Wei Liu ◽  
Yu Dong Xu
Keyword(s):  
Corrosion Rate ◽  
Base Metal ◽  
Corrosion Behavior ◽  
Heat Affected Zone ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Electroanalytical Chemistry ◽  
Microstructure Observation ◽  
Weight Loss Method ◽  
Loss Method

The influence of different flame of gas welding on corrosion behavior of the carbon steel’s heat affected zone in seawater were studied by the weight-loss method, electroanalytical chemistry method and surface and microstructure observation. The result indicate that when gas welding the carbon steel, the corrosion rate of the heat affected zone under the influence of mild carbonizing flame is 0.1252[g／(m2•h)], in contrast, the corrosion rate of that under the influence of neutral flame is 0.1025[g／(m2•h)]; the order of corrosion current shows as follows: Imild carbonizing flame>Ineutral flame>Ibase metal; the order of measured corrosion potential as follows: Ebase metal>Eneutral flame>Emild carbonizing flame. Compared with the base metal, the heat effected zone are more likely to corrosion, corrosion resistance of the sample under mild carbon flame are the worse.

scholarly journals Corrosion Behavior of Pure Cr, Ni, and Fe Exposed to Molten Salts at High Temperature

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
O. Sotelo-Mazón ◽  
C. Cuevas-Arteaga ◽  
J. Porcayo-Calderón ◽  
V.M. Salinas Bravo ◽  
G. Izquierdo-Montalvo
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Molten Salts ◽  
Refractory Compound ◽  
Open Circuit Potential ◽  
Passive Layer ◽  
Open Circuit ◽  
Metallic Surface ◽  
Weight Loss Method ◽  
Loss Method

Corrosion resistance of pure Fe, Cr, and Ni materials exposed in NaVO3molten salt at 700°C was evaluated in static air during 100 hours. The corrosion resistance was determined using potentiodynamic polarization, open circuit potential, and lineal polarization resistance. The conventional weight loss method (WLM) was also used during 100 hours. The electrochemical results showed that Fe and Cr have a poor corrosion resistance, whereas pure Ni showed the best corrosion performance, which was supported by the passive layer of NiO formed on the metallic surface and the formation of Ni3V2O8during the corrosion processes, which is a refractory compound with a higher melting point than that of NaVO3, which reduces the corrosivity of the molten salt. Also, the behavior of these materials was associated with the way in which their corresponding oxides were dissolved together with their type of corrosion attack. Through this study, it was confirmed that when materials suffer corrosion by a localized processes such as pitting, the WLM is not reliable, since a certain amount of corrosion products can be kept inside the pits. The corroded samples were analyzed through scanning electron microscopy.

Corrosion Behaviour of Aluminium Alloy in Palm Oil Methyl Ester (B100)

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
W. B. Wan Nik ◽  
S. Syahrullail ◽  
R. Rosliza ◽  
M. M. Rahman ◽  
M. F. R. Zulkifli
Keyword(s):  
Weight Loss ◽  
Methyl Ester ◽  
Corrosion Rate ◽  
Aluminium Alloy ◽  
Palm Oil ◽  
Corrosion Behaviour ◽  
Corrosion Current ◽  
Electrochemical Test ◽  
Weight Loss Method ◽  
Loss Method

The aim of this study is to determine the corrosion effect of palm oil methyl ester (POME) on aluminium alloy 5083 (AA5083). The static immersion test was carried out at 60°C for 68 days according to ASTM G–31–72. The corrosion analysis was done by using weight loss method and electrochemical test. The result from weight loss method shows the decreasing in weight loss of AA5083 which signifies the ability of POME to reduce corrosion rate. The electrochemical test shows the decreasing in polarization resistance,Rp, while the corrosion current densities, Icorr, increase. The corrosion rate reduces from 2.250mpy to 0.1946mpy. The low concentration of fatty acid C18:2 and high anti oxidant element contributes to the reduction of corrosion rate of AA5083 in POME.

Preparation and characterization emulsion of PANI-TiO2 nanocomposite and its application as anticorrosive coating

2015 ◽  
Vol 35 (6) ◽  
pp. 597-603 ◽  
Author(s):  
Mohsen Khademian ◽  
Hossein Eisazadeh
Keyword(s):  
Electron Microscopy ◽  
Colloidal Particles ◽  
Aqueous Media ◽  
Corrosion Current ◽  
Ammonium Persulfate ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Matrix ◽  
Definition Of

Abstract Emulsion nanoparticles of polyaniline (PANI) were synthesized in the aqueous media by using hydroxylpropylcellulose (HPC) as a stabilizer and ammonium persulfate as an oxidant in the presence of TiO2 with nanometer size. New poly(vinyl acetate) (PVAc) coating over carbon steel was prepared by addition of emulsion nanoparticles in different concentrations (1%, 2% and 1.5%) in PVAc as the major matrix. The Tafel plot records were used for the definition of potential and corrosion current (Icorr). Nanoparticles were characterized and compared by X-ray diffraction (XRD), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By adding TiO2, the thermal stability of the nanocomposite increased. A small size of colloidal particles prevented the precipitation of conducting polymer particles and led to better dispersion of nanocomposites in the matrix of the PVAc binder; therefore, the paint was homogeneous and anticorrosion properties of the coating increased. According to the results, 1.5% of PANI-TiO2 nanocomposite in PVAc has a much lower Icorr in NaCl aqueous solution and 2% of PANI-TiO2 nanocomposite in PVAc has the best corrosion protection in HCl.

scholarly journals Effect of Sn Addition on Microstructure and Corrosion Behavior of As-Extruded Mg–5Zn–4Al Alloy

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2069 ◽  
Author(s):  
Jian Ding ◽  
Xin Liu ◽  
Yujiang Wang ◽  
Wei Huang ◽  
Bo Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Corrosion Current ◽  
Electrochemical Measurements ◽  
Corrosion Mechanism ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Average Grain Size

The effect of Sn addition on the microstructure and corrosion behavior of extruded Mg–5Zn–4Al–xSn (0, 0.5, 1, 2, and 3 wt %) alloys was investigated by optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical measurements, and immersion tests. Microstructural results showed that the average grain size decreased to some degree and the amount of precipitates increased with the increasing amount of Sn. The extruded Mg–5Zn–4Al–xSn alloy mainly consisted of α-Mg, Mg32(Al,Zn)49, and Mg2Sn phases as the content of Sn was above 1 wt %. Electrochemical measurements indicated that the extruded Mg–5Zn–4Al–1Sn (ZAT541) alloy presented the best corrosion performances, with corrosion potential (Ecorr) and corrosion current density (Icorr) values of −1.3309 V and 6.707 × 10−6 A·cm−2, respectively. Furthermore, the corrosion mechanism of Sn is discussed in detail.

Microstructure and Electrochemical Properties of Ce-Containing 7072 Al Alloy

2013 ◽  
Vol 704 ◽  
pp. 114-119
Author(s):  
Jing Feng ◽  
Dong Yan Ding ◽  
Wen Long Zhang ◽  
Yong Jin Gao ◽  
Guo Zhen Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Properties ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Al Alloy ◽  
Nacl Solution ◽  
Tafel Polarization ◽  
Electrochemical Testing ◽  
Transmission Electron ◽  
Positive Effect

The microstructure and electrochemical properties of Ce-containing 7072 Al alloy were investigated through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Tafel polarization analysis. It was found that Ce alloying could result in a formation of finer grains in the simulated brazing alloys. The 7072 Al alloy with 0.15% Ce had desirable distribution of precipitates. The electrochemical testing results indicated that Ce element had a great impact on the corrosion potential of the alloy tested in 0.5% NaCl solution. Alloying with 0.15% Ce element could make the corrosion potential shift to inert direction and reduce the corrosion current density. An excessive Ce addition could weaken its positive effect on the corrosion resistance of the Ce-containing alloy.

Anti-Corrosion Properties of Composite WC-Ni Based Brazing Coatings

2011 ◽  
Vol 347-353 ◽  
pp. 1605-1608
Author(s):  
Da Quan Zhang ◽  
Li Xin Gao ◽  
Huan Wu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
316L Stainless Steel ◽  
Vacuum Furnace ◽  
Corrosion Properties ◽  
Mixed Powder ◽  
Weight Loss Method ◽  
Loss Method ◽  
Superior Corrosion Resistance ◽  
Scanning Electron

The flexible metallic cloth was made of mixed powder consisting of WC and organic blend. A brazing coating was obtained through the high temperature brazing of the metallic cloth in vacuum furnace. The anti-corrosion of the brazing coating was investigated by weight-loss method and electrochemical measurements. The surface morphology observation was conducted by the scanning electron microscopy (SEM). The results show that the composite coating has superior corrosion resistance compared with 316L stainless steel.

Microstructural Evolution and Deformation Mechanisms for Superplasticity of NiAl Intermetallic

2005 ◽  
Vol 475-479 ◽  
pp. 2995-2998
Author(s):  
Jian Ting Guo ◽  
Rong Shi Chen ◽  
Xing Hao Du ◽  
Gu Song Li ◽  
Lan Zhang Zhou
Keyword(s):  
Electron Microscopy ◽  
Microstructural Evolution ◽  
Superplastic Deformation ◽  
Tensile Elongation ◽  
Deformation Mechanisms ◽  
High Angle ◽  
Continuous Dynamic Recrystallization ◽  
Transmission Electron ◽  
Continuous Dynamic ◽  
Temperature Strain

The microstructural evolution during superplastic deformation of the extruded stoichiometric NiAl polycrystals were systemically investigated in various conditions of temperature, strain rate and strain by means of optical microscopy (OM) and transmission electron microscopy (TEM). Consequently, The deformation microstructures corresponding to the large tensile elongation consisted of subgrains, low angle grains as well as high angle grains, which indicated that continuous dynamic recrystallization (CDRX) process was operating during superplastic deformation.

scholarly journals New 3,3'-((4-Aryl) methylene)bis(4-hydroxy-2H chromen 2- one) (MHO) derivatives as Corrosion Inhibitor

2020 ◽  
Vol 10 (4) ◽  
pp. 137-146
Author(s):  
Yasameen K. Al-Majedy ◽  
Hiba H. Ibraheem ◽  
Ali Jasem ◽  
Ahmed A. Al-Amiery
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Weight Loss ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Corrosion Inhibitor ◽  
Weight Loss Method ◽  
Loss Method ◽  
Scanning Electron ◽  
Surface Technique

New green natural particles as corrosion inhibitor namely, macromolecules were incorporated beginning from 4-hydroxycoumarin with 4-nitrobenzaldehyde in the presence of glacial acid (1) then synthesis with methyl bromoacetate after that this compound (2) used to synthesis of 2,2'-(3,3'-((4-nitrophenyl)methylene)bis(2-oxo-2H-chromene-4,3 diyl))bis(oxy)diacetohydrazide (3) when was refluxed with hydrazine hydrate when compound(2) refluxed with HCl to obtain compound (4)  and tested all the synthesis compounds on mild steel (MS) in 1 M HCl, 1M H2SO4 media by a weight loss method and identification of the surface technique employee scanning/electron/microscope (SEM) studies. The weight loss investigation demonstrated that inhibition performances have been improved via concentration raising of inhibitor. To support our results scanning electron microscopy was employed to clarify the surface of the MS with and without synthesis compounds in 1.0 M HCl and1.0M H2SO4 media.

scholarly journals Ability to use of Robinia pseudoacania L fruit extract as a natural corrosion inhibitor in the protection of historical bronze objects

2020 ◽  
Author(s):  
vahid pourzarghan ◽  
bahman fazeli nasab
Keyword(s):  
Weight Loss ◽  
Sodium Chloride ◽  
Corrosion Rate ◽  
X Rays ◽  
Bronze Alloy ◽  
Sem Images ◽  
Corrosive Solution ◽  
Weight Loss Method ◽  
Loss Method ◽  
Inhibitory Power

Abstract Background: The phenomenon of bronze disease is considered as the most important factor in the destruction of bronze objects. Different methods have been proposed to cope with it. The most important inhibitors used in this regard are BTA and AMT(5-ami- no-2-mercapto-1,3,4-thiadiazole). While these inhibitors control the corrosion, they are toxic and cancerous. In the ideal conditions, these inhibitors are able to slow down the activity of chlorine ion, but they leave some side effects after a period of treatment. Today, plant extracts are used for this purpose. In this study, Robinia pseudoacania L extract was selected for this purpose.Material and methods: Natural inhibitor of Robinia fruit at concentrations of 200 ppm to 1800 ppm was evaluated in a corrosive solution of sodium chloride 0.5 M on a bronze alloy with a percentage similar to ancient alloys (Cu-10Sn) using potentiostat, weight loss method, and humidifier area.Results: Given the data derived from potentiostate device showed that Robinia pseudoacania L Inhibitory power at 1000 ppm with corrosion rate of 12.78% is 55% and the classic method of weight loss inhibitory power after four week at 1800 ppm Robinia pseudoacania L in contrast a corrosive solution of sodium chloride 0.5 M is 92% for bronze alloy (Cu-10Sn). In addition, SEM images suggest that the formation of film on the coupon has been flacked. While the results of the analyses suggest the inhibitory power of Robinia pseudoacania L, granular corrosion is evident on the coupons surfaces in SEM-EDX(Scanning Electron Microscope-Energy Dispersive X-rays) images and analysis.Conclusion: According to the SEM-EDX method, the acetate potential device and the classical weight loss method on bronze (Cu-10sn), the results show that the corrosion rate in the acetate potential method is 55%, while in the classical method the reduction is shown. The weight of this figure reaches 92%. It is important to note that the SEM images show a kind of grain boundary separation on the coupons of this alloy, which is due to the presence of this substance in the corrosive solution of sodium chloride.

Sign in / Sign up

Export Citation Format

Share Document