Corrosion in the News: August 3, 2020 Roundup
This week we take a look at radiation and its ability to slow corrosion rates, a new flame-resistant coating, an improved ultrasonic inspection method, and a corrosion risk for specific airplanes…
Welcome to the early August 2020 Corrosionpedia news roundup. Corrosionpedia releases a fresh news roundup every other week to provide a summary of the most important headlines in the world of corrosion prevention, monitoring and materials science. This edition covers an exciting discovery about radiation and its ability to slow corrosion rates rather than increase them. Other highlights in this edition include a new flame-resistant coating, an improved ultrasonic inspection method used to detect corrosion, and a proposed airworthiness directive due to the risk of corrosion on specific airplanes.
Radiation Discovered to Slow Corrosion on Certain Materials
Researchers at the Massachusetts Institute of Technology and Lawrence Berkeley National Laboratory have discovered that certain types of radiation can slow the rate of corrosion on some materials. The initial purpose of the research was to determine how much more rapidly corrosion would occur on several different nickel-chromium metal alloys covered in molten salt when exposed to radiation. However, the introduction of radiation into the experiment actually increased the ability to resist corrosion for some materials.
The discovery could potentially have a large impact on the nuclear power generation industry. Nuclear reactors could be designed in such a way that the metals used to construct the reactors benefit from the results of this experiment. This in turn would result in reduced downtime, repair and maintenance cost for nuclear power generation facilities.
Sherwin-Williams Expands Intumescent Coatings Line
Sherwin-Williams recently announced that it has added a product to its FIRETEX intumescent line of coatings. The new coating product is called FIRETEX M90/03, and it has been specifically designed for onshore equipment in the oil and gas industry. Intumescent coatings are typically used for fire protection because when heat is applied to them, they increase in volume while their density decreases. The result of this reaction insulates the underlying substrate from a fire and keeps the fire's elevated temperatures further from the substrate as the coating becomes more voluminous. One of the unique attributes of FIRETEX M90/03 is that it meets UL 1709 standards at multiple coating thickness levels, allowing a more efficient use of the coating across the substrate to which it is applied. Intumescent coatings are important for equipment used to process hydrocarbons because if fire is allowed to damage the coating, the substrate underneath can rapidly corrode.
Laird Creates New Products with Improved Corrosion Resistance
Laird Performance Materials, a global materials technology company, has recently developed two new products that have a high resistance to corrosion. The products are electrically conductive elastomers. The first product, EcE 130, is an electrically conductive fluorosilicone elastomer featuring a conductive passivated silver aluminum filler. The passivated silver aluminum helps it prevent and resist galvanic corrosion. EcE 135, the other product, is an electrically conductive fluorosilicone elastomer featuring a nickel aluminum filler. Both materials are primarily used as a sealant to protect military equipment in harsh environments such as saltwater, extreme heat and humidity. Unprotected materials in these environments are at a high risk of excessive corrosion.
Corrosion Causes FAA to Propose New Directive
The United States Federal Aviation Administration (FAA) has proposed a new airworthiness directive for several propeller-driven airplane models manufactured by the Aerostar Aircraft Corporation due to safety concerns caused by corrosion. Aerostar models PA-60-601P, PA-60-602P and PA-60-700P are all listed in the proposal because of corrosion found on some aileron and elevator tubes. According to the FAA document associated with the airworthiness directive proposal, if the corrosion were to become significant enough, the tube could jam, resulting in a loss of aircraft control. The directive would require inspection of the balance tubes and their replacement if excessive corrosion or rust were found.
Corrosion Causes Semi-Truck Recall
Over 150,000 Freightliner Cascadia trucks are being recalled because of corrosion found on several of the vehicles. Daimler Trucks North America, the parent company of Freightliner, issued the recall earlier in July when corrosion was found on a valve used for the antilock brakes. If corrosion progresses far enough, the Freightliner Cascadia models involved in the recall may pull to one side. Extreme scenarios of this could be enough to cause an accident. However, no accidents or injuries have been reported, and the recall is being used to prevent any major failures from occurring. The recall affects trucks produced from March 2016 to June 25, 2020. More information on the recall can be found on the National Highway Traffic Safety Administration website.
New Ultrasonic Inspection Method Developed
Researchers at the Indian Institute of Technology in Madras have recently created a new type of ultrasonic inspection method that can be used to more accurately inspect large structures for discontinuities and defects such as corrosion. The team began with the ultrasonic inspection method known as guided wave testing, which sends ultrasonic waves along the length of a substrate, allowing large lengths to be inspected at once. However, one of the current problems with guided wave testing is that the resolution suffers due to diffraction. By using metamaterials (materials that are synthetically created), the researchers have been able to improve upon this resolution issue, thus creating a guided wave testing procedure that can more accurately pinpoint defects such as excessive corrosion.