Corrosion of Carbon Steel Q235 in a Crevice Under a Simulated Disbonded Coating

CORROSION ◽  
10.5006/1224 ◽  
2014 ◽  
Vol 70 (7) ◽  
pp. 686-694
Author(s):  
Jin Xu ◽  
Cheng Sun ◽  
Maocheng Yan ◽  
Fuhui Wang
2012 ◽  
Vol 503-504 ◽  
pp. 247-250 ◽  
Author(s):  
Ping Zhao ◽  
Jia Xing Yang ◽  
Peng Peng Zhu ◽  
Cheng Sun ◽  
Jin Xu

The effect of sulfate reducing bacteria (SRB) on the corrosion of Q235 steel has been investigated in the crevice under the simulated disbonded coating with aperture width of 1.0 and 0.5mm in the soil-extract solutions (SES) by using electrochemical methods. The results show that the existence of SRB in SES can cause corrosion potential of the working electrode to shift to a more negative value, and the formation of pitting on the surface of the electrode. Compared with the crevice width of 1.0mm, the corrosion potential of the electrode shows a little more positive at the crevice width of 0.5mm. The corrosion rate of the electrode increases with the increase of aperture width in the SES without SRB, however, decreases with the increase of aperture width in the SES with SRB. The results obtained indicate that either bio-film on the surface of the electrode formed by SRB in SES or aperture width has obvious influences on the crevice corrosion process of the carbon steel.


Author(s):  
Y. L. Chen ◽  
J. R. Bradley

Considerable effort has been directed toward an improved understanding of the production of the strong and stiff ∼ 1-20 μm diameter pyrolytic carbon fibers of the type reported by Koyama and, more recently, by Tibbetts. These macroscopic fibers are produced when pyrolytic carbon filaments (∼ 0.1 μm or less in diameter) are thickened by deposition of carbon during thermal decomposition of hydrocarbon gases. Each such precursor filament normally lengthens in association with an attached catalyst particle. The subject of filamentous carbon formation and much of the work on characterization of the catalyst particles have been reviewed thoroughly by Baker and Harris. However, identification of the catalyst particles remains a problem of continuing interest. The purpose of this work was to characterize the microstructure of the pyrolytic carbon filaments and the catalyst particles formed inside stainless steel and plain carbon steel tubes. For the present study, natural gas (∼; 97 % methane) was passed through type 304 stainless steel and SAE 1020 plain carbon steel tubes at 1240°K.


2001 ◽  
Vol 81 (12) ◽  
pp. 2797-2808
Author(s):  
Rustem Bagramov, Daniele Mari, Willy Benoi

1993 ◽  
Vol 90 (7-8) ◽  
pp. 917-922
Author(s):  
Y. Matsuda ◽  
M. Nishino ◽  
J. Ikeda

2018 ◽  
Vol 18 (1) ◽  
pp. 125-135
Author(s):  
Sattar H A Alfatlawi

One of ways to improve properties of materials without changing the product shape toobtain the desired engineering applications is heating and cooling under effect of controlledsequence of heat treatment. The main aim of this study was to investigate the effect ofheating and cooling on the surface roughness, microstructure and some selected propertiessuch as the hardness and impact strength of Medium Carbon Steel which treated at differenttypes of heat treatment processes. Heat treatment achieved in this work was respectively,heating, quenching and tempering. The specimens were heated to 850°C and left for 45minutes inside the furnace as a holding time at that temperature, then quenching process wasperformed in four types of quenching media (still air, cold water (2°C), oil and polymersolution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°Cwith one hour as a soaking time for each temperature, then were all cooled by still air. Whenthe heat treatment process was completed, the surface roughness, hardness, impact strengthand microstructure tests were performed. The results showed a change and clearimprovement of surface roughness, mechanical properties and microstructure afterquenching was achieved, as well as the change that took place due to the increasingtoughness and ductility by reducing of brittleness of samples.


2020 ◽  
Vol 65 (1) ◽  
pp. 77-82
Author(s):  
Simona CAPRARESCU ◽  
◽  
Violeta PURCAR ◽  
Cristina MODROGAN ◽  
◽  
...  

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