NIGIS corrosion awareness awards – 2019
To commemorate Corrosion Awareness Day, NACE International Gateway India Section (NIGIS) will be presenting Corrosion Awareness Awards to honour individuals/institutions for their contribution to corrosion awareness and development in the field of corrosion science and technology in India during CORCON 2019 International Corrosion Conference and Exhibition during 23 – 26 September 2019 at CIDCO Exhibition & Convention Centre, Mumbai, INDIA with the theme as “Protecting People, Assets and the Environment”. The award carries a Plaque, Certificate & Honorarium.
Invitation of Applications for NIGIS Corrosion Awareness Awards are in the following categories:
- Excellence in Corrosion Science & Technology Awards
- Distinction in Corrosion Science & Technology Awards
- Excellent Laboratory Award
- Student Awards
- Meritorious Contribution Award
One could also contribute to this prestigious award program of NIGIS by informing others about the award program and eliciting their participation in the application process.
Further information can be had from:
Manager, Technical Services
NACE International Gateway India Section, 305-A, Galleria, Hiranandani Gardens, Powai, Mumbai – 400076
Website : www.naceindia.org / www.corcon.org
Using AI to detect – and predict – coating corrosion
The application of machine learning in a pilot project with Google Cloud and SoftServe moves classification one step closer to condition-based maintenance, says ABS director of technology Gu Hai. Image recognition powered by artificial intelligence (AI) is a proven technology in many fields, such as medicine, transportation and security.
In the maritime industry its potential is just beginning to be recognised and applied. In non-marine fields, the objects that the technology is asked to analyse tend to have well-defined charact¬eristics in terms of shape or colour. In shipping and offshore energy applications, the anoma¬lies that need to be detected and analysed are more random in shape, pattern and colour, which will make their assessment more complex. Potential visual impairments – such as mud or fouling on floating LNG (FLNG) vessels, floating production storage and offloading vessels or offshore platforms, different types of hull and structure coatings and difficulty of access and uneven lighting – add to the challenge.
About four years ago, class society ABS began work on the use of image recognition to support visual inspections with a Singapore university, in a joint development project (JDP) to develop a proof of concept in a marine environment. Building on this JDP, ABS began to look for potential industry partners to further develop this capability and ultimately make it available for commercial applications.
“Our concept was that a machine learning-based image recognition tool should be able to identify and detect anomalies in the ship or offshore structure and quality of coatings from photographic data alone. This would assist surveyors in assessing the development of corrosion or coating failure and also lay the groundwork for a more predictive approach to maintenance”, he said.
ABS shared its ideas about the use of AI-based machine learning with a number of companies, including Google Cloud, which saw this as a good application for its Cloud AutoML and open-source machine learning package, TensorFlow, in a test environment. With an initial agreement in place, ABS could undertake a feasibility study on the basis that if Google Cloud chose to proceed, it would provide a product via its third-party platform partner, SoftServe.
The pilot project ran for about one month, using photos taken from both ships and offshore platforms by surveyors on regular class inspections. Typically, a surveyor must manually assess a structure for corrosion or coating breakdown and give a rating of the condition. Whether the coating is in good, fair, or poor condition is the driver to whether the owner needs to act.
Current practice combines the surveyor's experience with simple charts or other reference material to generate a rating on the coating's condition. The rating is based on the percentage of the area that is corroded, but the surveyor does not physically measure this area of corrosion, instead using their judgement to make a determination.
The image-recognition tool ABS designed can be calibrated to detect the total area of corrosion or coating breakdown and calculate the area pixel-by-pixel, to give an accurate and consistent report on the corroded area. This means that it can be used to analyse any type of marine structure onshore or offshore, provided it is trained with sufficient data to make the assessment.
One of the drivers for the development of this technology is that in future more and more inspections will be made remotely, using technology such as drones or crawlers. Remote inspection technologies include remotely operated platforms or vehicles such as drones and crawlers, platforms which are used to inspect hard-to-reach places, such as confined spaces, at height, and underwater. In addition to reducing the risks associated with sending surveyors inside tanks or other confined spaces, these technologies generate a far greater volume of photographic data to analyse and interpret. Because the ABS in-house image library has a sufficient volume of information, the pilot project used existing photographic data sourced from ABS surveyors.
Teaching the neural network
To make this type of AI work accurately the machine learning tool must be trained with sufficient data to recognise different types of coating failures and structural components, such as hull stiffeners and plates. This machine learning tool is in fact a type of 'neural network'. The normal process of employing this type of tool is firstly to identify the most appropriate neural network because there are many different versions available, each designed for a different purpose. After testing a number of neural networks, we selected the most suitable for the pilot study and trained it with data; in our case photos of corrosion. A neural network has many parameters, making it is necessary to adjust the parameters in training in order to get it to respond with the information we wanted to know.
To accurately identify the presence and location of corrosion or coating breakdown on the image, all the photos needed to be tagged, requiring intervention by an ABS engineer to examine each image and mark the affected area, noting the extent and severity of the corrosion. This would tell the neural network where the corrosion is visible and how serious it is. This meant tagging a large number of photos to cover all the scenarios we might find on a ship or other structure, not least because there are many different types of coatings in multiple colours and the degree of corrosion can be different based on the level of exposure. For each neural network in the pilot, a few hundred photos were used, 80% of them for training and the other 20% for testing the accuracy of its answers. Once the neural network was trained, it was able to detect and recognise corrosion by taking a raw photographic input, detect the corrosion on the image and overlay the corroded area in a different colour on the image. Because the neural network was able to identify the location of the corrosion it could calculate the corroded area pixel-by-pixel, providing a rating using criteria from ABS Rules based on its evaluation percentage.
The pilot project with Google Cloud and SoftServe delivered promising results and the next stage will see further in-house testing and evaluation by ABS. A timescale for full scale commercialisation or when the system will be employed in the field has not yet been finalised. What is certain is that this type of machine learning moves ABS towards its stated goal of offering condition-based surveys and being able to provide more predictive analysis as part of the class inspection process.
This 'condition-based class' approach is made possible because of AI's ability to consistently analyse images which enables the prediction of the future condition of coatings and corrosion by analysing historical data. If enough data can be accumulated using multiple images of the same area of coating, then over a period of time it will be possible to make predictions based on its likely future evolution. In being able to bring a predictive approach to asset management, ABS believes that AI-driven inspections on ships and offshore assets bring potential benefits for safety, accuracy and efficiency.
Northwestern University researchers devise new Self-healing coating strategy for metals
A research team at Northwestern University has developed a new coating strategy for metal that self-heals within seconds when scratched, scraped, or cracked. The novel material could prevent these tiny defects from turning into localized corrosion.
“Localized corrosion is extremely dangerous,” said Jiaxing Huang, a materials science and engineering professor who led the research. “It is hard to prevent, hard to predict, and hard to detect, but it can lead to catastrophic failure.” The project was supported financially by the U.S. Office of Naval Research.
When damaged by scratches and cracks, Huang's patent-pending system readily flows and reconnects to rapidly heal. The researchers demonstrated that the material can heal repeatedly, even after scratching the exact same spot nearly 200 times in a row.
While a few self-healing coatings already exist, those systems typically work for nanometer- to micron-sized damages, according to the researchers. To develop a coating that can heal larger scratches in the millimeter-scale, Huang and his team looked to fluid. “When a boat cuts through water, the water goes right back together,” Huang said. “The 'cut' quickly heals because water flows readily. We were inspired to realize that fluids, such as oils, are the ultimate self-healing system.”
But common oils flows too readily, Huang explained. So his team needed to develop a system with contradicting properties: fluidic enough to flow automatically, but not so fluidic that it drips off the metal's surface.
Lightweight particle network
The team met the challenge by creating a network of lightweight particles — in this case, graphene capsules — to thicken the oil. The network fixes the oil coating, keeping it from dripping. But when the network is damaged by a crack or scratch, it releases the oil to flow readily and reconnect.
Huang believes the material can be made with any hollow, lightweight particle, and not just graphene. “The particles essentially immobilize the oil film,” Huang said. “So it stays in place.”
According to the researchers, the coating sticks well even in underwater and harsh chemical environments, such as acid baths. Huang envisions that it could be painted onto bridges and boats that are naturally submerged underwater, as well as metal structures near leaked or spilled highly corrosive fluids. The coating can also withstand strong turbulence and stick to sharp corners without budging. When brushed onto a surface from under water, the coating goes on evenly without trapping tiny bubbles of air or moisture that often lead to pinholes and corrosion.
Further information from:
Northwestern University Department of Materials Science and Engineering, USA(847) 491-3537, www.northwestern.edu
MegaRust 2019 Naval Corrosion Conference Opens
THE US based MegaRust 2019 Naval Corrosion Conference was held at the Renaissance Portsmouth-Norfolk Waterfront Hotel in Portsmouth, Virginia, USA. MegaRust is conducted annually to provide a consolidated focus on corrosion issues faced by the U.S. Navy. According to event organizers, corrosion is a major factor in the readiness and total ownership cost of naval systems.
As such, the conference is intended to provide updated information on programs, policies, standards, and Fleet experience related to corrosion and to promote discussion and sharing of information on technologies and strategies for controlling corrosion.
The conference provides an impartial forum for dialogue between government and commercial organizations, as well as providers of coatings and corrosion control products, processes, technologies, and solutions.
Participants include representatives from military, industry, and government organizations involved with research and development, design, engineering, construction, maintenance, modernization, and operation of naval systems that are potentially affected by corrosion. The conference covers all segments of the naval services including sea, air, Marine Corps, vehicles, and facilities.
The event also featured live demonstrations, in which attendees sawthe equipment and coatings regularly used for shipboard maintenance on U.S. Navy vessels. Exhibiting companies included Blast One; NCP Coatings Inc.; Norton Sandblasting; PPG; Sherwin-Williams; and Sulzer Mix-Pac.
The agenda featured numerous technical sessions related to coatings, along with a keynote address from Robert Herron who serves as director of corrosion policy and oversight in the Office of the Deputy Assistant Secretary of US Defense for Material Readiness.
A220 and E2 compressor hub corrosion cuts its life limit
AIRBUS A220 and Embraer E2 operators are being advised of cycle limit amendments to the high-pressure compressor hub on their Pratt & Whitney engines. The measure is being taken after corrosion on a front hub was discovered during routine engine overhaul.
"This corrosion, also found beneath the anti-corrosion coating, reduces the low-cycle fatigue capability and can occur even during engine downtime," says a proposed US FAA directive.
It says the engine manufacturer has reduced the certified life of the affected front hub of the high-pressure compressor.
The condition could lead to cracking before the component reaches its life limit, potentially resulting in uncontained release of the hub and possible damage to the powerplant and aircraft. A220s are fitted with the PW1500G engine while the E2 family is powered by the PW1900G.
Cortec releases new coatings guides
CORROSION control technologies company Cortec (St. Paul, Minnesota, USA) recently released three new coatings information sheets.
The first handout highlights the company's removable coatings that serve as convenient replacements to COSMOLINE and Tectyl. Options include solvent-, oil-, and water-borne coatings that can be applied for storage and transit protection and easily removed using alkaline cleaners.
The second information sheet features VpCI-391, a popular removable anticorrosion coating that dries to a thin, clear film that is virtually unnoticeable.
Meanwhile, the third sheet introduces an alternative to blasting on rusty surfaces. The CorrVerter rust primer allows end users to eliminate the blast and coat the rust with a passivating primer. The primer can be topcoated with water- or solvent-borne topcoats, including urethanes, epoxies, acrylics, and alkyds.
The three information sheets can be accessed at the company's web site.
Magnetohydrodynamic galvanizing modernizes corrosion prevention for steel applications
A MAGNETOHYDRODYNAMIC galvanizing setup, when turned off, demonstrates a common problem in galvanizing: excess zinc runoff (top left). When the ID wiper is turned on, the system runs efficiently, eliminating excess zinc consumption. A third concerns magnetism. While it's usually considered an attractive force, magnetism repels some elements and compounds, including bismuth, copper, lead, silver, mercury, zinc, and water. When they are announced, such discoveries generally are little more than scientific curiosities, and for most of us, that's the end of it. It's unlikely that any of us really care about the relativity of time or a gravitational field so strong it can't be measured, but the third one, known as diamagnetism, has practical applications.
Suspension in a coil
The key to applying a new or unusual concept in physics to solve a real-world problem is to find the right equipment to make it work. Diamagnetism isn't a strong force, so it needs a powerful magnetic field to turn it into a useable force.
A specific electromagnet, the Bitter solenoid, is very powerful. Invented in 1933 by Francis Bitter, this type of solenoid creates extremely strong continuous magnetic fields. Because its shape is a coil, it exerts a magnetic force focused in the center of the windings. A diamagnetic item, such as a length of copper wire, placed in the center of an energized Bitter solenoid will be repulsed from all directions around the solenoid's circumference, essentially trapping it.
A Bitter solenoid's magnetic field is more than strong enough to capture and contain a quantity of water, holding it in suspension.
For a practical application, the team at SunWyre Inc. created a system that captures and contains molten zinc in the same way. It went on to develop the necessary equipment and a process to apply the zinc to the surface of steel objects that pass through the suspended zinc. Galvanizing is nothing new, but this process, termed magnetohydrodynamic (MHD) galvanizing, provides an updated way to apply the zinc and control its thickness. MHD was developed nearly 30 years ago, so it's not a new technology, but it is new to the tube and pipe industry.
“The system uncoils the wire rod, prepares the surface, galvanizes it, and recoils the wire rod so it's ready for shipment or further processing,” he said. The company installed systems throughout the Americas and in the Middle East, continuing to expand the technology's worldwide presence.
Tube and pipe applications
Several years later a tube producer inquired about the technology. “In 2007, a tube producer in Australia asked about continuous galvanizing for its products,” Dorsten said. “The application called for galvanizing round tube, then reshaping it to be rectangular or square.” SunWyre developed a system for this application, and after entering the tube market, it was just matter of time before finding other tube and pipe applications.
“A common galvanized product in the automotive industry is Galfan,” Dorsten said. Developed in the 1980s and named for galvanizing with fantastic properties, the process uses about 95 percent zinc, 5 percent aluminum, and some rare-earth metals to provide a coating that is more durable and corrosion resistant than 100 percent zinc, according to industry literature. Applied at the same coating thickness as zinc, Galfan provides longer-lasting protection; alternatively, the Galfan thickness can be reduced to achieve protection similar to that of straight zinc. “For many automotive applications, the coating thickness is 9 or 10 microns,” Dorsten said. “Some of the automotive suppliers wanted a thicker coating, and it took us about a year to perfect it, but we got it up to 24 microns in a consistent application,” he said. A thicker coating leads to a longer life cycle, so the new product has been nicknamed Super-Galfan, Dorsten said. Subsequent applications include structural steel, conduit, and rebar.
Rebar is galvanized in either of two ways. The most common involves low-carbon steel billets, 41⁄4 by 41⁄2 in., which are hot-rolled to reduce the size to 0.375 to 2 in. diameter. The hot-rolling processes also imparts the rib pattern. Sizes from 3⁄8 to ½ in. dia. can be galvanized by uncoiling, galvanizing, and recoiling it. Larger diameters are galvanized in straight lengths. The equipment setup for MHD includes an induction heater to bring the workpiece up to the necessary temperature, 850 degrees F; a furnace equipped with a kettle that stores the zinc; and a Sweet coil, a device developed by SunWyre, which wipes the tube's OD, keeping any excess galvanizing compound in the galvanizing chamber. Because induction heating is fast, bringing a common tube sizes up to the galvanizing temperature in just a half second or so, line speeds up to 300 feet per minute are possible. While continuous processing lines exist, they're rare in tube and pipe applications. For the most part, MHD lines for tubular products handle cut lengths.
Further information from:SunWyre, www.sunwyre.com
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