WEDNESDAY, SEPTEMBER 26, 2018
A team of researchers from Arizona State University has taken a new angle on the idea of stress corrosion cracking, showing in a new study that corrosion and stress needn’t be present simultaneously in order to bring about SCC.
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| Photo by CEphoto, Uwe Aranas?, CC BY-SA 3.0, via Wikimedia Commons |
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SCC occurs when a corrosive environment and stress both impact a susceptible material, leading to structural damage. |
SCC occurs when a corrosive environment and stress both impact a susceptible material, leading to structural damage. The phenomenon has been blamed for catastrophic failures, including the collapse of the Silver Bridge, in Point Pleasant, West Virginia, in 1967, which killed 46 motorists.
New Information on SCC
Previously, the ASU team explains, conventional wisdom held that corrosion must be ongoing while a structure is subjected to stress in order for SCC to occur. But the researchers’ new article, “Decoupling the Role of Stress and Corrosion in the Intergranular Cracking of Noble Alloys,” published earlier this month in Natural Materials, shows that the same phenomenon can occur even if corrosion occurs, then the material is subjected to stress later.
"The finding is the culmination of about 30 years' work on this kind of stress corrosion problem," said lead researcher Karl Sieradzki, a professor of materials science and engineering at ASU. "We now have a view into how new alloys can be designed to avoid this form of stress corrosion-induced failure."
The researchers looked at intergranular stress corrosion cracking using a silver-gold alloy; they found that while the nature of the corrosion that contributes to SCC lends the appearance of simultaneity between the corrosion and stress that brings the cracking on, in fact the corrosion can lay the groundwork for SCC in advance of tensile stress.
The research could help in the development of new alloys for the formulation of new alloys for the construction of structures like nuclear plants, where significant environmental factors increase the risk for corrosion.
Tagged categories: Colleges and Universities; Corrosion; Maintenance + Renovation; Research; Steel
