Corrosion in the News: July 01, 2019 Roundup
This week's stories take a look at several failures that were caused by corrosion and some new corrosion prevention improvements such as coatings and material innovations.
Welcome to the early July edition of the Corrosionpedia News Roundup. The Corrosionpedia News Roundup is where we give you the information you need to be up to date and aware of what is going on in the vast world of corrosion science. For this roundup, we have a couple corrosion and coating happenings going on in the Midwest region of the United States. Other interesting and recent corrosion-related events include passenger ferries failing inspection as a result of corrosion, a new inspection method for rebar coatings, and more.
Coating Cracks on Chicago Skyscraper
The Willis Tower in Chicago, Illinois had a minor coating failure earlier this June. The coating on the Skydeck, the Willis Tower’s viewing platform for tourists, began to crack as people were walking on it. The protective coating has little structural importance, and mostly serves as a way to protect the underlying material from degradation and corrosion. However, the tourists on the deck were unaware of this as it cracked around them, giving them a scare. Willis Tower officials have confirmed that it was minor cracking, and that there was no danger. The coating has already been replaced and the Skydeck is open again for viewing.
New Aluminum Battery Enclosure for Electric Vehicles Developed
Novelis, an industrial aluminum giant, has designed a new aluminum battery enclosure for the burgeoning electric car industry. The aluminum battery enclosure promises to offer many advantages over traditional steel battery enclosures. Because it is aluminum, it will not be able to rust. This lessens the risk of corrosion-induced failure, which is especially important for car battery enclosures that are often subjected to conditions that cause accelerated corrosion.
In addition to corrosion resistance, the aluminum enclosure developed by Novelis will be approximately 50% lighter than a comparable steel battery enclosure. Novelis isn't manufacturing the enclosures, but will provide the aluminum and advise companies on how to make their own battery enclosures.
Michigan Tests New Corrosion Monitoring Techniques
The Michigan Department of Transportation in the United States has begun testing a new method of concrete bridge inspection. The method involves mounting a camera system, known as a three-dimensional optical bridge evaluation system, to vehicles and sending them underneath the bridge being inspected.
Traditional bridge inspection methods involve employees spending time inspecting the bridge manually, which has high labor costs and often involves lane closures and subsequent traffic slowdowns. The three-dimensional optical bridge evaluation system can detect cracks and corrosion without requiring the extra labor and lane shutdowns. While it is currently only being used to supplement traditional inspection methods, there may be a day where it could replace some traditional inspection techniques.
New Inspection Method Developed for Rebar Corrosion
A University of Saskatchewan doctoral student recently invented a new method to determine the soundness of rebar coatings. Reinforcing steel bar, or rebar, is commonly used in many applications, most notably concrete reinforcement. However, if the rebar corrodes then the concrete structure could fail. Other rebar coating inspection methods are destructive and could also unintentionally affect test data. Arthur Situm, the Ph.D. student, found a way to test these coatings nondestructively using radiographic equipment and particle accelerators. The project was funded by multiple sources, several of which are mining companies concerned with how the salts involved in mining degrade their concrete structures.
Ferries in New Orleans Fail Inspection Again, Corrosion Partly to Blame
Corrosion issues, among other concerns, have caused two passenger ferries in the southern United States to fail their inspections. The New Orleans Regional Transit Authority recently purchased the two ferries from Metal Shark, a local shipbuilding company. With regard to corrosion, there is concern about whether the contact points between dissimilar metals have been adequately addressed. This is a concern because dissimilar metal contact could induce rapid galvanic corrosion. Some corrosion has already occurred. There are also other issues unrelated to corrosion, but the transit authority and Metal Shark plan to move forward with plans to pass the inspection criteria.
Additive Titanium Application Replaces Aluminum in the Aerospace Industry
Norsk Titanium, a leader in titanium additive manufacturing processes, has recently delivered to Spirit Aerosystems its first ever additive manufactured titanium component for a commercial airplane. The titanium fitting, made for the access door of several new Boeing 787’s, is FAA-approved, making it a huge milestone accomplishment as the aerospace industry continues to pursue titanium components as well as additive manufactured parts. The benefit of titanium alloys over other aerospace alloys such as stainless steels and aluminums is increased corrosion resistance. (Related reading: 3 Truths About Titanium Dioxide Corrosion Prevention.) While titanium doesn’t typically have the strength that stainless steel does, it is half the weight, which is extremely important for fuel efficiency reasons.