scholarly journals Time Dependent Development of Aluminium Pitting Corrosion

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Robert E. Melchers
Keyword(s):  
Pitting Corrosion ◽  
Aluminium Alloys ◽  
Corrosion Behaviour ◽  
Uniform Corrosion ◽  
Dependent Development ◽  
Practical Applications ◽  
Excellent Corrosion Resistance ◽  
Gradual Development ◽  
Power Law Function

Aluminium alloys have excellent corrosion resistance to a wide variety of exposure conditions. Usually they corrode by pitting rather than by uniform corrosion. For infrastructure applications long-term corrosion behaviour is of interest. The relatively limited long-term pitting data that is available shows that maximum and average pit depths do not follow the power law function as conventionally assumed but tend to follow a bimodal trend with exposure time. This is consistent with the bimodal trends observed previously for corrosion mass loss of aluminium alloys. Most likely it is the result of the accumulation of corrosion products over the pit mouths, leading to the gradual development of localised anoxic conditions within pits. In turn this permits the development within the pits of anoxic autocatalytic conditions, consistent with established theory for pitting corrosion of aluminium. It also is consistent with observations of hydrogen evolution from pits. The implications of this for practical applications are discussed.

A Numerical Model for the Corrosion of Copper Nuclear Fuel Waste Containers

1995 ◽  
Vol 412 ◽  
Author(s):  
F. King ◽  
M. Kolář
Keyword(s):  
Nuclear Fuel ◽  
Corrosion Potential ◽  
Corrosion Behaviour ◽  
Temporal Variations ◽  
Localized Corrosion ◽  
Uniform Corrosion ◽  
Adsorbed Species ◽  
Maximum Period ◽  
Nuclear Fuel Waste

AbstractA model is presented for the prediction of the long-term corrosion behaviour of Cu nuclear fuel waste containers. The model is based on a kinetic description of the processes involved in the uniform corrosion of Cu in a conceptual Canadian disposal vault. The 1-dimensional, multilayer model accounts for mass-transport, electrochemical and chemical processes and predicts the spatial and temporal variations of the concentrations of various dissolved, precipitated and adsorbed species, as well as the time dependence of the corrosion rate and the corrosion potential (ECORR). The variation of [O2], [Cu(II)] and ECORR with time can also be used to predict the maximum period over which localized corrosion processes, such as pitting or stress corrosion, may occur. Predictions from the model suggest that 25-mm-thick Cu containers will not fail due to uniform corrosion or pitting in periods <106 a.

Modelling the Effects of Evolving Redox Conditions on the Corrosion of Copper Containers

1993 ◽  
Vol 333 ◽  
Author(s):  
F. King ◽  
D. M. LeNeveu ◽  
D. J. Jobe
Keyword(s):  
Nuclear Fuel ◽  
Waste Disposal ◽  
Corrosion Behaviour ◽  
Redox Conditions ◽  
Uniform Corrosion ◽  
Corrosive Environment ◽  
Change Over Time ◽  
Nuclear Fuel Waste ◽  
Over Time

ABSTRACTThe corrosive environment around the containers in a Canadian nuclear fuel waste disposal vault will change over time from “warm and oxidizing” to “cool and anoxic”. As the conditions change, so too will the corrosion behaviour of the containers. For copper containers, uniform corrosion and, possibly, pitting will occur during the initial aggressive phase, to be replaced by slow uniform corrosion during the long-term anoxic period.The corrosion behaviour of copper has been studied over a range of conditions representing all phases in the evolution of the vault environment. The results of these studies are summarized and used to illustrate how a model can be developed to predict the corrosion behaviour and container lifetimes over long periods of time. Lifetimes in excess of 106 a are predicted for 25-mm-thick. copper containers under Canadian disposal conditions.

A Ten Step Mechanism for the Pitting Corrosion of Aluminium Alloys

1997 ◽  
Vol 15 (3-4) ◽  
pp. 471-496 ◽  
Author(s):  
M.C. Reboul, ◽  
T.J. Warner, ◽  
H. Mayer, ◽  
B. Barouk,
Keyword(s):  
Pitting Corrosion ◽  
Aluminium Alloys ◽  
Step Mechanism

scholarly journals Issues Related to Late-Life Sexuality: Sex in Long-Term Care

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 602-602
Author(s):  
Rachael Spalding ◽  
Peter Lichtenberg
Keyword(s):  
Best Practice ◽  
Long Term Care ◽  
Social Stigma ◽  
Late Life ◽  
Assessment Tools ◽  
Geographical Differences ◽  
Term Care ◽  
Practical Applications ◽  
Ethical And Legal Issues

Abstract Despite surrounding social stigma and stereotypes of the “asexual older adult,” older adults, including those residing in long-term care facilities, indicate that expressing their sexuality continues to be important to them (Doll, 2013). This presentation will feature presentations regarding recent research and perspectives relevant to late-life sexuality with a focus on how issues of sexual expression may particularly emerge in long-term care settings. Dr. Maggie Syme will present findings from mixed-methods, consumer-based approaches that elucidate how current and future long-term care residents view late-life sexuality, with a focus on the practical applications of these findings to inform facility administration and policies. Ethical and legal issues surrounding sexuality in long-term care will be discussed by Dr. Pamela Teaster, who will present ethical models that can translate into potential best-practice recommendations and strategies. Rachael Spalding will discuss the paucity of psychometrically sound assessment tools for measuring attitudes towards late-life sexuality and discuss their development of such a measure. Finally, Dr. Lilanta Bradley and Dr. Pamela Payne-Foster will present a framework for sexual agency in late-life and identify relevant gaps in the literature regarding gender, ethnicity/race, and geographical differences. Ultimately, this presentation will offer a forum for lively discussion among attendees regarding these pertinent topics.

Stainless Steels With Improved Oxidation Resistance for Recuperators

2004 ◽  
Vol 128 (2) ◽  
pp. 370-376 ◽  
Author(s):  
Bruce A. Pint
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Oxidation Resistance ◽  
Stainless Steels ◽  
Lower Cost ◽  
Exhaust Gas ◽  
New Materials ◽  
Excellent Corrosion Resistance ◽  
Gas Environment

New materials are being evaluated to replace type 347 stainless steel in microturbine recuperators operating at higher temperatures in order to increase the efficiency of the microturbine. Commercial alloys 120 and 625 are being tested along with potentially lower cost substitutes, such as Fe-20Cr-25Ni and Fe-20Cr-20Ni. Long-term testing of these materials at 650–700 °C shows excellent corrosion resistance to a simulated exhaust gas environment. Testing at 800 °C has been used to further differentiate the performance of the various materials. The depletion of Cr from foils of these materials is being used to evaluate the rate of attack. Although those alloys with the highest Ni and Cr contents have longer lives in this environment, lower alloyed steels may have sufficient protection at a lower cost.

Pitting Corrosion Behaviour of Boron Added Modified 9Cr–1Mo Steel: Combined Effects of Alkali and Chloride Ions

2014 ◽  
Vol 68 (1) ◽  
pp. 129-141 ◽  
Author(s):  
Namrata Upadhyay ◽  
M. G. Pujar ◽  
C. R. Das ◽  
Nanda Gopal Krishna ◽  
C. Mallika ◽  
...  
Keyword(s):  
Pitting Corrosion ◽  
Corrosion Behaviour ◽  
Chloride Ions ◽  
Combined Effects

The effect of hydroquinone and methoxypropylamine on the pitting corrosion behaviour of A-470 low alloy turbine disc steel

1993 ◽  
Vol 34 (8) ◽  
pp. 1289-1297 ◽  
Author(s):  
V Otieno-Alego ◽  
G.A Hope ◽  
H.J Flitt ◽  
D.P Schweinsberg
Keyword(s):  
Pitting Corrosion ◽  
Corrosion Behaviour ◽  
Turbine Disc
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