Comparative Study on the Cyclic Corrosion Test of Rail Steel U68CuCr and U75V

2012 ◽  
Vol 616-618 ◽  
pp. 1059-1062
Author(s):  
An Chao Ren ◽  
Huan Zhou ◽  
Min Zhu ◽  
Ze Xi Yuan
Keyword(s):  
Corrosion Resistance ◽  
Comparative Study ◽  
Corrosion Test ◽  
Rail Steel ◽  
Rust Layer ◽  
Corrosion Tests ◽  
Corrosion Rates ◽  
Cyclic Corrosion

A further investigation into the determination of corrosion resistance behavior has been carried out through a series of cyclic corrosion tests in order to comparatively study the corrosion rates of rail steel U68CuCr and U75V under different cycle conditions. The results indicate that U68CuCr possesses better corrosion resistance than U75V. According to macroscopic view, colors of U68CuCr surfaces are all lighter than those of U75V in the same group. Moreover, the grains at the rust layer of U68CuCr specimens show much finer and denser microstructure than U75V. Besides, cracks on the rust layer of U75V specimens are found.

scholarly journals Effect of Oxide Scale Microstructure on Atmospheric Corrosion Behavior of Hot Rolled Steel Strip

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 517
Author(s):  
Bin Sun ◽  
Lei Cheng ◽  
Chong-Yang Du ◽  
Jing-Ke Zhang ◽  
Yong-Quan He ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Oxide Scale ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Corrosion Test ◽  
Atmospheric Corrosion ◽  
Corrosion Mechanism ◽  
Type I ◽  
Rust Layer ◽  
Hot Rolled

The atmospheric corrosion behavior of a hot-rolled strip with four types (I–IV) of oxide scale was investigated using the accelerated wet–dry cycle corrosion test. Corrosion resistance and porosity of oxide scale were studied by potentiometric polarization measurements. Characterization of samples after 80 cycles of the wet–dry corrosion test showed that scale comprised wüstite and magnetite had strongest corrosion resistance. Oxide scale composed of inner magnetite/iron (>70%) and an outer magnetite layer had the weakest corrosion resistance. The corrosion kinetics (weight gain) of each type of oxide scale followed an initial linear and then parabolic (at middle to late corrosion) relationship. This could be predicted by a simple kinetic model which showed good agreement with the experimental results. Analysis of the potentiometric polarization curves, obtained from oxide coated steel electrodes, revealed that the type I oxide scale had the highest porosity, and the corrosion mechanism resulted from the joint effects of electrochemical behavior and the porosity of the oxide scale. In the initial stage of corrosion, the corrosion product nucleated and an outer rust layer formed. As the thickness of outer rust layer increased, the corrosion product developed on the scale defects. An inner rust layer then formed in the localized pits as crack growth of the scale. This attacked the scale and expanded into the substrate during the later stage of corrosion. At this stage, the protective effect of the oxide scale was lost.

Corrosion of Cobalt and Cobalt Alloys

CORROSION ◽  
1969 ◽  
Vol 25 (7) ◽  
pp. 307-322 ◽  
Author(s):  
F. R. MORRAL
Keyword(s):  
Crystal Structure ◽  
Corrosion Resistance ◽  
Alloy Composition ◽  
Surface Preparation ◽  
Cobalt Alloys ◽  
Effect Data ◽  
Corrosion Rates ◽  
Effect Of Impurities ◽  
Cobalt Base

Abstract Investigations are reviewed of the composition and structures of corrosion films and scales found on cobalt and on simple and complex cobalt-base industrial alloys. The corrosion resistance of these films and scales depends on metal and alloy composition, environment (an atmosphere containing one or more of CO2, S, H2S, O2, H2O, SO2, V2O3, NaCl, etc.), pressure, temperature, and time. Additional factors, alone or in combination, such as surface preparation, stress, thermal shock, geometry of the part, velocity, density, and flow pattern of the corroding environment also have an effect. Data on oxidation, sulfidation, and hot corrosion (a combination of the first two) of cobalt and its alloys are summarized in some detail, as are the known characteristics of the films and scales that are formed. Only the work that used techniques permitting determination of composition and crystal structure of these films and scales was reviewed. The effect of impurities in metals and alloys may be as significant as that of added alloying elements; impurities may alter the scales' chemical and physical properties—increasing, decreasing, or neutralizing corrosion rates. Until data are available on the intereffect on diffusion of elements present in scales, films, and metal surfaces, the mechanisms of corrosion proposed are only hypotheses.

Effect of Ni Alloying on the Corrosion Resistance of 355MPa High Weather-Resistant Steel

2015 ◽  
Vol 816 ◽  
pp. 781-787
Author(s):  
Z.R. Hou ◽  
H.L. Yi ◽  
X.M. Zhao
Keyword(s):  
Corrosion Resistance ◽  
Weathering Steel ◽  
Resistant Steel ◽  
Rust Layer ◽  
Corrosion Tests ◽  
Ni Content

Based on the 355MPa high weather-resistant steel, three different kinds of high weather-resistant steels were designed by varying the content of Ni. The the corrosion resistance of the high weather-resistant steel as well as the influence of Ni content on the corrosion resistance were studied in the present investigation. The results of the cycle corrosion tests indicated that with the addition of Ni, the corrosion resistance was improved to some extent. The rust layer of the weathering steel was composed of α-FeOOH and γ-FeOOH at the beginning of corrosion, and the α-FeOOH turned to γ-FeOOH which enhanced the corrosion resistance.

IMPROVING THE CORROSION RESISTANCE OF RЕM–Fe–B MAGNETS

2021 ◽  
pp. 97-107
Author(s):  
D.S. Gorlov ◽  
◽  
I.V. Cherednichenko ◽  
R.A. Valeev ◽  
D.V. Chesnokov ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Plasma Coating ◽  
Comparative Assessment ◽  
Vacuum Arc ◽  
Corrosion Tests ◽  
Ion Plasma ◽  
Cyclic Corrosion

The article presents the results of work on improving the corrosion resistance of magnets of the REM–Fe–B system manufactured in China, by applying an ion-plasma coating of the SDP-1T + VSDP-13 system on an industrial vacuum-arc installation MAP-3. A comparative assessment of the tread protection of the vacuum-arc coating of the SP-1T + VSP-13 system was carried out with an already applied Ni–Cu–Ni coating under conditions of accelerated cyclic corrosion tests at a temperature of 300 °C. The coating of the SDP-1T + VSDP-13 system, applied in the FSUE «VIAM», creates a much more resistant protection of the magnets of the REM–Fe–B system from corrosion compared to the electroplating of the Ni–Cu–Ni system, manufactured in China.

Susceptibility of Automobile Spring Steels to Wet-Dry Cyclic Corrosion Induced Environmental Embrittlement

2005 ◽  
Vol 297-300 ◽  
pp. 933-938
Author(s):  
K. Kobayashi ◽  
Shinichi Komazaki ◽  
Toshihei Misawa ◽  
T. Fukuzumi
Keyword(s):  
Significant Influence ◽  
Pitting Corrosion ◽  
Experimental Results ◽  
Strength Level ◽  
Nacl Solution ◽  
Rust Layer ◽  
Corrosion Tests ◽  
Environmental Embrittlement ◽  
Cyclic Corrosion ◽  
Spring Steels

The susceptibility to environmental embrittlement (EE) of automobile spring steels was investigated using six different steels. A SSRT test and TDS analysis were applied to specimens subjected to wet-dry cyclic corrosion tests in a NaCl solution. Experimental results revealed that the reduction in ductility after the corrosion tests was pronounced with increasing strength level. This degradation was closely associated with the resistance to pitting corrosion. Consequently, the hydrogen absorbed in steel and the corrosion pit as a geometric damage were responsible for the EE of spring steels. The hydrogen in rust layer had no significant influence on the EE.

Effects of Mg Additions on Surface Morphology and Corrosion Resistance of Hot-Dipped Zn Coatings

2008 ◽  
Vol 273-276 ◽  
pp. 300-305 ◽  
Author(s):  
Lucia Suarez ◽  
Frans Leysen ◽  
C. Masquelier ◽  
D. Warichet ◽  
Yvan Houbaert
Keyword(s):  
Corrosion Resistance ◽  
Construction Material ◽  
Coating Properties ◽  
Surface Layers ◽  
Corrosion Tests ◽  
X Ray ◽  
Cyclic Corrosion ◽  
Wide Range ◽  
Excellent Method

Steel is still the main construction material for automobiles, general equipment and industrial machinery. Hot dipping has been proven to be an excellent method of corrosion protection of steels for a wide range of applications worldwide. Coatings of Zn-Al alloys on steel sheet have high corrosion resistance due to the corrosion prevention ability from Zn and the passivation of Al Bath composition, immersion velocity/time and substrate composition are the hot dipping parameters that more influence on the thickness and corrosion resistance of the deposited coating. In order to study their influence small amounts of magnesium were added. Experiments were performed in a hot dipping simulator using different substrates, bath compositions and hot dipping parameters. Surface layers were characterised by: Scanning Electron Microscopy (SEM) and Energy dispersive X-Ray spectroscopy (EDX or EDS). Cyclic corrosion tests were performed in order to observe the corrosion resistance for different Zn-Al-Mg coatings. Results show that the microstructure and composition of the substrate strongly affect the desired coating properties. Nevertheless, the influence of the magnesium on coating thickness is relevant, increasing when added in small quantities in a molten bath of Zn-5wt %Al. The quality and microstructure of the coating is affected by the amount of Mg in the bath. Cyclic corrosion tests results show that the quality of the coating is affected by the amount of Mg in the bath.

The Impact of In Situ-Formed Spinel on the Porosity of No-Cement Refractory Castables

2017 ◽  
Vol 908 ◽  
pp. 139-144
Author(s):  
Lenka Nevřivová
Keyword(s):  
Corrosion Resistance ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Corrosion Test ◽  
Corundum Refractory ◽  
Refractory Castables ◽  
The Impact ◽  
Furnace Slag

The paper focuses on the determination of how in-situ formed magnesia-alumina spinel (MA spinel) content in corundum refractory castables influences the final properties and pore size distribution of no-cement refractory castables. The motivation for this research was the continued pressure on increasing the utility properties of refractory castables, namely their corrosion resistance to blast-furnace slag. The influence of MA spinel content was observed in vibration-compacted refractory castables (three mixtures). The corrosion test was performed to determine the dependence of the size of the slag-penetrated area on MA spinel content in the specimen. The pore structure of a slag-penetrated NCC and an unaffected castable was described.

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