Server maintenance is scheduled for Saturday, December 21st between 6am-10am CST.

During that time, parts of our website will be affected until maintenance is completed. Thank you for your patience.

Menu
Search
Filters
Close
Menu

Understanding Atmospheric Corrosion Damage On An Aircraft Representative Galvanic Specimen: A Two-Pronged Approach That Combines Modeling With Experimental Measurement

Picture for Understanding Atmospheric Corrosion Damage On An Aircraft Representative Galvanic Specimen: A Two-Pronged Approach That Combines Modeling With Experimental Measurement
Available for download

Aircraft representative galvanic test articles and witness coupons were placed out for atmospheric exposure testing at the U.S. Naval Research Lab (NRL) site in Key West, Florida. One set of test specimens was exposed to only ambient environment for a 62 day period; a second set of test specimens was exposed to both ambient environment (initial 62 days), and a short duration, twice daily, seawater spray protocol over a further 55 day period. Environmental loading was monitored using sensors that measured temperature, relative humidity, rainfall, and time of wetness (TOW), at 30 minute intervals. Following retrieval, the test articles were inspected in the laboratory using laser profilometry to characterize the spatial distribution and depth of corrosion damage. Mass loss measurement using the witness coupons was used to estimate relative corrosion rates for the two periods.

Product Number: 51322-17638-SG
Author: Thomas Curtin, Robert Adey, Andres Peratta
Publication Date: 2022
Industries: Corrosion Monitoring and Control , Coatings and Linings , Coatings
$0.00
$20.00
$20.00

A comprehensive modeling exercise was undertaken to better understand, the spatial distribution of corrosion damage, measured on aircraft representative, galvanic test articles, exposed to two significantly different corrosive environments. One set of test articles was exposed to ambient conditions in a coastal marine environment for approximately two months, while a second set was further exposed to controlled seawater spray dosing for an additional two months. Both environmental loading scenarios are assessed, analyzed, and modeled. The performance of a three-dimensional (3D) finite element model, of the multi-material galvanic test article, is discussed, along with some of the challenges associated with selecting appropriate input parameters to best represent the two different exposure conditions. The measured spatial distribution of corrosion damage is compared to the galvanic simulation model solutions. A complex pattern of corrosion damage is observed, that includes, localized galvanic corrosion at the fastener, crevice corrosion beneath the bushing flange, and galvanic interaction between the fastener and larger diameter bushing. The sensitivity of the models to electrolyte resistance (film thickness, conductivity) and extent; and the metal resistance (polarization curves), representing each environment, are explored.

A comprehensive modeling exercise was undertaken to better understand, the spatial distribution of corrosion damage, measured on aircraft representative, galvanic test articles, exposed to two significantly different corrosive environments. One set of test articles was exposed to ambient conditions in a coastal marine environment for approximately two months, while a second set was further exposed to controlled seawater spray dosing for an additional two months. Both environmental loading scenarios are assessed, analyzed, and modeled. The performance of a three-dimensional (3D) finite element model, of the multi-material galvanic test article, is discussed, along with some of the challenges associated with selecting appropriate input parameters to best represent the two different exposure conditions. The measured spatial distribution of corrosion damage is compared to the galvanic simulation model solutions. A complex pattern of corrosion damage is observed, that includes, localized galvanic corrosion at the fastener, crevice corrosion beneath the bushing flange, and galvanic interaction between the fastener and larger diameter bushing. The sensitivity of the models to electrolyte resistance (film thickness, conductivity) and extent; and the metal resistance (polarization curves), representing each environment, are explored.

Product tags
Also Purchased
Picture for Very High Strength Low Alloy Steels For HPHT Applications
Available for download

Very High Strength Low Alloy Steels For HPHT Applications

Product Number: 51322-17721-SG
Author: Florian Thebault, Julien Pennequin, John Fortaillier, Carine Landier
Publication Date: 2022
$20.00

More and more High Pressure High Temperature (HPHT) sour wells are operated worldwide. Challenging material selection is required for such severe operating conditions.1,2 Very high strength materials, presenting yield strength above 896 MPa (130 ksi), are required for sustaining the pressure. Consequently, even a low amount of H2S in the gas phase may lead to a H2S partial pressure beyond the limit of 3.5 mbar (0.05 psi) established in NACE MR0175 / ISO 15156 standard.3 Indeed, both high yield strengths and partial pressures of H2S contribute to a situation where the risk of Sulfide Stress Cracking (SSC) is high. The present paper is focusing on the SSC resistance of 130 ksi minimum yield strength material developed for covering such HPHT applications.
Use Of Vapor Phase Corrosion Inhibitor For Tank Bottom Protection
Available for download

Use Of Vapor Phase Corrosion Inhibitor For Tank Bottom Protection

Product Number: 51322-17879-SG
Author: Muhammad A. Sherwani
Publication Date: 2022
$20.00

EWPD of Saudi Aramco is the custodian of five large volume crude oil storage tanks with diameter of 106 m (348’) and 110 m (360’), where the crude oil is stored and transported from eastern region to western region. The tank which is being addressed in this paper is an API1 650 with floating roof. Its capacity is 1,013,000 barrels and its diameter is 110 m. This tank was built in 1978 on an oily sand pad and reinforced concrete ring wall. The inboard and sketch plates are 6.35 mm thick, and annular plates are 16 mm thick 
Picture for Understanding Effect Of Scribe Method On Variability In Accelerated Corrosion Test Results
Available for download

Understanding Effect Of Scribe Method On Variability In Accelerated Corrosion Test Results

Product Number: 51322-17897-SG
Author: Sarah Specht
Publication Date: 2022
$20.00

The coatings industry has made widespread use of a variety of accelerated test methods to quickly and effectively evaluate coating performance. Such accelerated methods are advantageous for predicting coating system performance where real-time testing is impractical. For example, it is not practical to evaluate coatings in harsh environments where coatings are expected to last for decades when the pace of innovation and new coating development is faster than the test time would need to be. Therefore a variety of test methods exist to evaluate coatings on metal substrates, such as steel or aluminum. Coatings that will be subjected to corrosive environments require testing in environments to simulate the effects of corrosion, typically involving exposure to moderate salt concentration and elevated temperatures for a specified amount of time. Such tests, testing environments, and evaluation methods include ASTM B117,ISO 9227, and ISO 12944, to name a few.
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support