Corrosion Propagation Behavior Research Articles

Corrosion propagation of steel reinforcement in pre-cracked mortar attacked by seawater using wire beam electrode

A novel custom-designed wire beam electrode (WBE) covered by uncracked and cracked mortar was applied to study the corrosion propagation behavior of steel reinforcement. The results showed that WBE technique can effectively monitor passivation and pitting corrosion, especially for the propagation of corrosion. Mortar with a 0.1 mm crack could facilitate the initial corrosion of steel, and a 0.3 mm crack would enhance corrosion tendency dramatically, reaching a corrosion current density of 0.76 μA/cm2 after 300 d of seawater wetting-drying cycles. The corrosion propagation of wire electrodes is mainly determined by chloride distribution, which changes with increasing crack width.

Corrosion Propagation Behavior of low-Cr steel Rebars in Simulated Concrete Environments

Corrosion Propagation Behavior of low-Cr steel Rebars in Simulated Concrete Environments

Investigation of Microstructure and Corrosion Propagation Behaviour of Nitrided Martensitic Stainless Steel Plates

Martensitic stainless steels are commonly used for fabricating components. For many applications, an increase in surface hardness and wear resistance can be beneficial to improve performance and extend service life. However, the improvement in hardness of martensitic steels is usually accompanied by a reduction in corrosion strength. The objective of this study is to investigate the effects of nitriding on AISI 420 martensitic stainless steel, in terms of microstructure and corrosion propagation behavior. The results indicate that the microstructure and phase composition as well as corrosion resistance were influenced by nitriding temperatures.

Materials and Corrosion 9/2013

Materials and CorrosionVolume 64, Issue 9 Cover PictureFree Access Materials and Corrosion 9/2013 First published: 20 September 2013 https://doi.org/10.1002/maco.201370091AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Cover: The difference in corrosion propagation behavior of 316LN stainless steel and carbon steel concrete reinforcing bar is highlighted on the cover. The top images of 316LN stainless steel rebar (left) and polished corrosion coupon (right) show areas of deep, localized corrosion while the bottom images of carbon steel rebar (left) and polished corrosion coupon (right) show widespread, shallow corrosion damage. The difference in how corrosion spreads during electrochemical testing on arrays of 100 microelectrodes of both 316LN stainless steel and carbon steel is shown graphically. The grids represents a microelectrode array with red shading indicating stable anodic dissolution. The middle two rows were preferentially initiated and the 316LN array showed no spreading to adjacent electrodes (top) while corrosion on the carbon steel array rapidly spread to adjacent electrodes (bottom). The rebar composition and manner which corrosion propagates will directly impact the lifetime of the concrete structure. More detailed information can be found in: M. F. Hurley, J. R. Scully, Lateral and radial corrosion propagation behavior of 9−21% Cr and 18% Cr + 2.8% Mo stainless steel reinforcing materials in simulated concrete environments, Materials and Corrosion 2013, 64, 752. Volume64, Issue9September 2013 RelatedInformation

Lateral and radial corrosion propagation behavior of 9–21% Cr and 18% Cr + 2.8% Mo stainless steel reinforcing materials in simulated concrete environments

AbstractThe life of a concrete structure exposed to deicing compounds or seawater is often been limited by chloride induced corrosion of the steel reinforcement. A complete assessment of the potential benefits afforded by new candidate rebar alloys must address both the lateral and radial corrosion propagation behavior in comparison to conventional steel as well as other factors that might affect the risk of corrosion‐induced concrete cracking. The radial (depth) and lateral (length) corrosion propagation behavior of 18% Cr + 2.8% Mo (S31653) stainless steel, 21% Cr (S32101) duplex stainless steel, and 9% Cr steel compared to plain ASTM A615 carbon steel were characterized in saturated Ca(OH)2 solution. Radial pit growth was found to be Ohmically controlled for all materials but repassivation occurred more readily at high applied potentials for 18% Cr + 2.8% Mo and 21% Cr stainless steels. Conversely, pit growth on plain steel propagated at all applied anodic potentials and did not repassivate until deactivation by cathodic polarization. Stainless steel also showed the highest resistance to lateral corrosion propagation from an active site during microelectrode array testing. 21% Cr duplex stainless and 9% Cr steel showed similar radial propagation behavior and corrosion morphology, which was intermediate to that of plain steel and S31653 stainless steel. Based on an existing concrete cracking model, it is expected that 9–21% Cr and 18% Cr + 2.8% Mo corrosion resistant rebar materials would require a greater depth of corrosion attack than carbon steel before damaging concrete via corrosion product formation.

コンクリート中におけるステンレス鉄筋の腐食進展挙動

コンクリート中におけるステンレス鉄筋の腐食進展挙動

Corrosion Propagation Behavior of Magnesium Alloys under Atmospheric Conditions

To investigate corrosion mechanisms of magnesium alloys under atmospheric conditions, field exposure tests were performed. In a marine environment, magnesium alloys experienced localized corrosion, including pitting and filiform corrosion. To reproduce such actual atmospheric corrosion in a laboratory experiment, we employed a wet-dry cyclic test at a constant dew point. From the results of the wet-dry cyclic tests, the propagation mechanism of localized corrosion on magnesium alloys has been discussed. Localized corrosion occurred during the wetting period, and the corroded sites thus formed were repassivated during the drying period. In the next wetting period, new localized corrosion took place, but the repassivated sites were not reactivated. The repassivated sites have higher corrosion resistance than the non-corroded part of the surface because of the barrier effect of the corrosion products. In the case of AZ91D, Al enrichment in the surface region of the metal matrix is responsible for this corrosion resistance.

Corrosion Propagation Behavior of Magnesium Alloys under Atmospheric Conditions

not Available.

Localized corrosion of alloy 22 in the potential Yucca Mountain repository environment

The U.S. Department of Energy (DOE) has indicated that it may use Alloy 22 as the waste package outer container material for the potential high-level waste repository at Yucca Mountain, Nevada. Additionally, a drip shield, made of titanium grade 7 and titanium grade 29, may extend the length of the emplacement drifts to enclose the top and sides of the emplaced waste package. Localized corrosion in the form of crevice corrosion could be one degradation process that may adversely affect the waste package performance. This paper will summarize the work conducted to evaluate the effects of environmental conditions relevant to the potential Yucca Mountain repository, metallurgical states (e.g., mill-annealed and welded plus solution annealed), and similar and dissimilar metal crevices on the crevice corrosion susceptibility of Alloy 22. This work also evaluates crevice corrosion propagation behavior resulting from contact with Alloy 22 or titanium grade 7.

Corrosion Propagation Behavior of New Metallic Rebar Materials in Simulated Concrete Environments and Engineering Implications

The radial (depth) and lateral (length) corrosion propagation behavior of 316LN stainless steel, 2101 LDX duplex stainless steel, and MMFX-2 compared to plain carbon steel were characterized in saturated Ca(OH)2 with NaCl additions. Radial pit growth was ohmically controlled for all materials but repassivated more readily at high potentials in the case of 316LN and 2101 LDX stainless steels. Conversely, pit growth on carbon steel propagated at all applied anodic potentials and did not repassivate until deactivation by cathodic polarization. Stainless steel showed the highest resistance to lateral corrosion propagation from an active site during microelectrode array testing. In contrast, carbon steel was found to easily undergo widespread depassivation along the surface compared to stainless steel. 2101 LDX duplex stainless and MMFX-2 showed similar radial propagation behavior and corrosion morphology, which was intermediate between carbon steel and 300 series type stainless steel.

Corrosion of similar and dissimilar metal crevices in the engineered barrier system of a potential nuclear waste repository

Crevice corrosion is considered possible if the corrosion potential ( E corr) exceeds the repassivation potential for crevice corrosion ( E rcrev). In this study, potentiodynamic polarization and potentiostatic hold were used to determine the E rcrev of similar and dissimilar metal crevices in the engineered barrier system of the potential Yucca Mountain repository in 0.5 M NaCl, 4 M NaCl, and 4 M MgCl 2 solutions at 95 °C. The results were compared with data previously obtained using crevices formed between Alloy 22 and polytetrafluoroethylene. It was observed that, except for Type 316L stainless steel, all other metal-to-metal crevices were less susceptible to crevice corrosion than the corresponding metal-to-polytetrafluoroethylene crevices. Measurements of galvanic coupling were used to evaluate the crevice corrosion propagation behavior in 5 M NaCl solution at 95 °C. The crevice specimens were coupled to either an Alloy 22 or a Titanium Grade 7 plate using metal or polytetrafluoroethylene crevice washers. Crevice corrosion of Type 316L stainless steel propagated without repassivation. For all the tests using a polytetrafluoroethylene crevice washer, crevice corrosion of Alloy 22 was initiated at open circuit potential by the addition of CuCl 2 as an oxidant, whereas no crevice corrosion of Alloy 22 was initiated for all the tests using Alloy 22 or Titanium Grade 7 metals as crevice washer. However, crevice corrosion propagation was found to be very limited under such test conditions.

Corrosion Propagation Behavior of New Metallic Rebar Materials in Simulated Concrete Environments

not Available.