Site Search:

Corrosion News

NACE International wins esteemed IACET 2018 innovation of the year award

The International Association for Continuing Education and Training (IACET) has named NACE International as the recipient of its esteemed 2018 Innovation of the Year Award for Technology Integration.

The IACET Innovation of the Year Award – Technology Integration recognizes the “best-of-the-best” in technology integration and innovation. “With the high-quality, competitive submissions the Awards Committee received, selecting the 2018 recipient was a significant challenge for the committee. We congratulate and honor NACE International for its achievement,” said Carol Martsoff, Chair - 2018 Awards Committee, IACET.

NACE International's virtual training simulator program for its cathodic protection (CP) education is a 12-station virtual training program which allows students to refresh CP skills, keep up with current practical techniques and prepare for CP classes and exams. The simulators enable students to work through step-by-step, real-life testing scenarios that are encountered in a live CP environment.

“This award is especially gratifying as I believe the ability to integrate and leverage digital technology into our products and services is not just key to our future, but absolutely critical in the coming digital age,” said Bob Chalker, NACE International CEO. “The fourth industrial revolution is being driven by a fusion of technologies and is blurring the lines between the physical, digital, and biological spheres. It is critical for NACE to be ready for this revolution. Being recognized for our innovation in education is a great indicator we are on the right path.”

Recognition of NACE by IACET highlights the work of NACE's Education and Information Technology departments. “A very large part of this award belongs to our IT team,” said Pam Nicoletti, NACE International Director of Education, “we are grateful to our IT team not only for their work on the simulators, but for the impressive technology and integration they bring to the organization every day.”

SSPC Protective Coatings Inspector (PCI) program reapproved by the American Bureau Of Shipping (ABS)

SSPC has announced that the organization has received reaffirmation from the American Bureau of Shipping (ABS) of its Certificate of Compliance for the SSPC Protective Coatings Inspector (PCI) training and certification program.

The PCI program is an intensive one week program designed to thoroughly train students in the proper methods of inspecting surface preparation and the installation of industrial and marine protective coating and lining systems on a wide variety of steel structures. It is one of several coating inspector programs offered by SSPC, including the Bridge Coatings Inspector (BCI) program, Concrete Coatings Inspector (CCI) program, the NAVSEA Basic Paint Inspector (NBPI) course, and the new Fireproofing Inspector program.

"SSPC is proud of the PCI program, which has trained/certified over 5,000 coating inspectors since its launch in 2007. Engineers, project managers and consultants have come to regard PCI as a go-to program for training on Quality Assurance, Quality Control, Surface Preparation and Inspection, to stay on the cutting edge of their profession,” stated Jennifer Merck, Director of Training and Certification at SSPC.

ABS completed a thorough curriculum review and audit and found PCI to be aligned with the ABS Guide for Certification of Maritime Education Facilities and Training Courses (G-CMET), IMO Resolution MSC.215(82), IACS Procedural Requirement No. 34 and Section 6 of the IACS Unified Interpretation Sc223.

Originally approved by ABS in 2008, the new certificate for PCI is valid through September 30, 2023.

To learn more about SSPC Protective Coatings Inspector (PCI) and how to register for the course, please click here: http://www.sspc.org/trn-crs-pci

SSSPC standards review committee member openings in 2019

The SSPC Standards Review Committee has openings for 2 new members in the consultant/architect/engineer demographic category and 1 member in the contractor demographic category starting in January 2019. SRC members are appointed by the SSPC President for renewable 3-year terms.

Qualified candidates for SRC appointment must belong to one of the above demographic categories and should have a 3-year history of SSPC membership that includes active participation on at least two SSPC Technical Committees.

The Standards Review Committee oversees development and processing of SSPC standards by reviewing both proposals for new standards and standards that have completed committee consensus development, including any unresolved negatives and objections. The SRC then votes either to recommend Board approval of the completed standard or to return the standard to the developing committee for additional work.

SSPC members interested in volunteering for the SSPC Standards Review Committee should contact Aimée Beggs (beggs@sspc.org, 412-288-6042).

Rolls-Royce jet engines hit by corrosion problems

Rolls-Royce has warned of fresh problems affecting around 200 of its engines, further damaging the engineer's reputation for reliability. The company has revealed that about one in 10 of its Trent 700 engines need repairs because of corrosion to turbine blades.

Rolls-Royce has discovered a problem with its Trent 700 engines

Rolls told operators of the engine, which powers the Airbus A330 airliner, that the problem does not require an immediate fix.

A spokesman for the company said that issue affects the high pressure turbine on engines that have been “operating in a particular environment", causing the corrosion.

Trent 700s are one of Rolls' most profitable engines, with the company currently building its 2,000th unit at its Derby base.

Rolls-Royce already faces problems with the Trent 1000 engine that powers Boeing's 787-9 Dreamliner jet after two carriers revealed they have had to ground aircraft because of faulty turbines. Rolls-Royce last year disclosed it would have to replace the turbine blades on the entire fleet of Trent 1000 engines powering the 787 after corrosion and cracking problems were discovered on some passenger jets operated by Japanese launch customer ANA. The turbine blade problems are the latest chapter in what has been a difficult early life for the Trent 1000 engine. Introduced into service six years ago, the engine has had several adjustments to rectify fuel burn and reliability issues, which are estimated to have pushed up the development cost of the turbine.

Pioneering Chevron technology solves Kazakhstan industry's pipeline challenges

Pipeline corrosion is a major challenge faced by the global oil and gas industry, as a corroded pipeline presents a clear risk to the environment and for the companies responsible.

The main obstacle in preventing corrosion is that materials may wear down over time from oil or gas moving through the pipeline, and coating and inspecting metal pipelines are the primary corrosion prevention measures. Another approach is switching to alternative pipeline materials such as polyethylene.

While conventional polyethylene pipelines experience difficulties in adverse temperatures, Chevron's polyethylene pipe plant in Atyrau has pioneered the production of Polyethylene with Raised Temperature Resistance (PE-RT) since 2003.

To support Tengizchevroil's (TCO) Future Growth Project-Wellhead Pressure Management Project (FGP-WPMP), the Atyrau plant initiated a Europe-wide search for suppliers of a suitable raw material for a water injection system upgrade, necessary for meeting water injection requirements.

The plant was also tasked with the production of a 20 kilometre pipeline for water transportation. Given the water's toxicity and high temperature, the search was on for technology which could meet the plant's rigid requirements. After three years of rigorous assessment, the Dow Chemical Company's PE-RT Type II technology was selected for implementation. This marked one of the first applications of the innovative material to industrial pipes in the oil and gas industry.

PE-RT pipeline technology use enabled the modernisation of TCO's water injection system, improving the transportation of the highly corrosive water produced at Tengiz oil field in the Atyrau region.

“There are many added benefits to using PE-RT. Its service life of 50 years is approximately 10 times that of traditional pipeline materials. It is also less costly than metal pipelines, which require cathodic protection, inhibitors and more regular inspection,” said the plant's Commercial Manager Yevgeniy Legin.

“Our use of this technology at TCO and FGP-WPMP is yet another example of how we are using innovation to safely and effectively unlock opportunities,” he added.

A Comparison of the corrosion response of zinc-rich coatings with and without presence of carbon nanotubes

In an article published in Corrosion Journal, Electrochemical impedance spectroscopy tests were conducted on carbon nanotubes (CNTs) enriched zinc-rich epoxy coating and a commercial zinc-rich coating. Coating performances were examined after exposure to a corrosive environment (a CO2 saturated aqueous electrolyte with 2,000 ppm chloride concentration and pH 3.5 to 5.3) at an elevated temperature of 60°C. The coatings' response after solid particle impingement erosion was also studied. Equivalent circuit models were proposed to elucidate the degradation mechanisms of the zinc-rich coatings under the synergic effect of corrosion and erosion. Results showed that the addition of CNTs into zinc-rich coatings provided better barrier protection for the steel substrate than traditional zinc-rich coatings in the noneroding environment. However, the CNT-filled zinc-rich epoxy coatings did not provide adequate protection when the coated specimens were exposed to an erosive and corrosive environment. CNTs could help with maintaining continuous electrical paths within zinc-rich coatings; however, the conductivity of the coating decreased significantly when zinc particles were partially oxidized. When defects caused by erosion are present in the coatings, CNTs may form galvanic couples with the steel and thus increase the corrosion rate of steel substrate.

For the applications where erosion is not a primary concern, addition of CNTs to zinc-rich coatings is extremely beneficial. ZRPCNT coatings with 75 wt% of zinc load could provide better barrier protection for the steel substrate than ZRP coating with higher zinc load.

The enhancement of electrical conductivity by CNTs decreased significantly when zinc particles within the zinc-rich coating were partially oxidized. When abrasion of the coating occurs and the specimens are exposed to a corrosive environment, the presence of CNTs in the zinc-rich coatings is not particularly helpful in providing cathodic protection to the steel substrate.

CNTs can enhance the electrical conductivity in the zinc-rich with a lower concentration of Zn particle. However, with 75 wt% of zinc concentration, the zinc-rich coatings could no longer maintain the porous structure and thus make it difficult for the electrolyte to reach the substrate. To increase the galvanic protection properties of the CNTs-Zn coatings, coatings with increased amount of zinc concentration should be examined.

Article Citation: Dailin Wang, Elzbieta Sikora, Barbara Shaw, A Comparison of the Corrosion Response of Zinc-Rich Coatings with and Without Presence of Carbon Nanotubes Under Erosion and Corrosion Conditions, CORROSION. 2018;74(11):1203-1213. https://doi.org/10.5006/2743

Korropad—a rapid corrosion test for stainless steels

Stainless-steel piping and tanks have a passive layer that protects them from corrosion. If this layer is incompletely formed or damaged, it can pose problems. Dr Helga Leonhard and Jens Lehmann discuss a rapid test that can be used to check the condition of the passive layer.

KorroPad test can indicate a defect in the passive layer. (Image courtesy: BAM)

A flawless passive layer on the material surface of stainless steel is essential. However, it is not always easy to ascertain whether the passive layer has fully formed and how to positively influence the quality of the natural surface protection during processing.

While they provide clarity on corrosion behaviour, traditional test methods, such as electrochemical measurements and salt-spray tests, they do require special equipment and expert knowledge so can be costly. Further, they are destructive test methods and can take hours or even days to gain a result. This makes such test unfeasible from a financial and practical perspective for many processors.

The KorroPad rapid test method, developed by the Bundesanstalt für Materialforschung und -prüfung (BAM), and verified by TÜV SÜD Chemie Service, changes this situation. In order to select the right materials, plant engineering routinely relies on electrochemical measurement methods, such as determination of pitting potential by plotting current density-potential-curves in measurement cells in a lab or at individual locations on the component itself. The objective was to compare electrochemical measurements with the KorroPad method. If the KorroPad method proved suitable, processors and users of stainless steels would be provided with an easy-to-use on-site method.

A shining, clean stainless steel surface is not necessarily an indicator that the right type of piping or tank material has been selected. Faults in, or inadequate formation of, the passive layer are not visible to the naked eye. In the chemical industry in particular, material surfaces have to withstand extreme conditions. During everyday production operations they are exposed to acids, corrosive gases and other aggressive fluids. Defects in the passive layer can lead to dissolution of materials and pitting corrosion, and ultimately causes failure. For this reason verification of the corrosion resistance of materials is important.

Passive layer

Plant engineering mostly uses chromium-nickel-molybdenum steel, with chromium being the most primarily important element for corrosion resistance. The presence of humidity and oxygen causes passivation, resulting in the formation of a chromium oxide layer on the stainless steel surface. The requirement for passivation is a chromium content of at least 10.5%. The chromium oxide layer acts as a passive layer. However, it is only a few atom layers thin, is invisible and highly sensitive. Faulty or unfavourable conditions during production, processing, transport or storage can affect full formation of the passive layer and this will affect surface protection. The passive layer can regenerate in the presence of a sufficient amount of oxygen and humidity. Ultra-clean polished metallic surfaces also favour repassivation.

If the passive layer is incomplete, divalent ferrous ions are released from the material at the faults in the protective layer. The gel-like KorroPads are saturated with water containing small amounts of sodium chloride and a ferrous-ion indicator. The indicator is potassium hexacyanoferrate (III), which is yellow to transparent in aqueous solution and spontaneously changes to Prussian blue upon contact with the ferrous ions released from the material. Highly visible blue spots appear on the light-yellow pads, indicating the locations at which the protective passive layer is missing on the stainless steel surface or has not fully formed.

Non-destructive test method

The KorroPad procedure is a non-destructive testing method. It can be used to verify the corrosion resistance of piping and tank components even before they are installed in a process plant.

Indications of corrosion and requirements for surface corrosion resistance (Image courtesy: BAM)

The test is easy to use and does not require any previous or expert knowledge in the fields of corrosion or electrochemistry. The KorroPads are roughly the size of a five Euro cent coin. The surface to be tested needs to be cleaned with acetone or alcohol before the pads are placed on the surface and pressed down. The test only takes 15 minutes. When this period has passed, the pads are removed using a plastic spatula and placed on a plastic carrier film. Scanning or photographing the test result is helpful for evaluation and documentation. If the KorroPads reveal a risk of corrosion, the material experts will consult with the plant operator and plan the next steps.

The test method is primarily surface-specific and can be used on all relevant stainless steel types. This was confirmed in comprehensive practice tests carried out on austenitic chromium-nickel-molybdenum steels at TÜV SÜD Chemie Service. Tests conducted on temper colours after welding also – without exception – produced indications in KorroPads. The testers further observed that electrochemical cleaning/polishing using devices designed for this purpose or mechanical treatments (such as brushing the weld seams) also sometimes resulted in indications. Obviously temper colours had not been sufficiently removed which hindered full re-formation of the passive layer.

Parallel to KorroPad testing in practice, TÜV SÜD Chemie Service carried out local electrochemical measurements for comparison. The results showed that pitting corrosion potential was lower at the points where KorroPad testing resulted in indications, meaning that corrosion risk is higher at these locations. This rapid test can also be used to verify that passivation has fully developed after grinding, etching and other cleaning steps, confirming that no problems need be expected during operation later on. It was also possible to prove that the rapid test is suitable for quality assurance. The method clearly identified faults on the exterior of new pipes with longitudinal welds.

On the safe side

TÜV SÜD Chemie Service confirmed the suitability of the KorroPad method in many tests and applications in practice. The method can be used to verify the corrosion resistance of steels both as delivered and after processing. Given this, it provides clarity and reliability in corrosion protection right from the outset. The method can also be used to characterise many process-related factors influencing surface quality and material. Thanks to its rapid application and the easy evaluation of test results, the method enables both positive and negative changes in passive-layer stability to be identified immediately. This allows users to respond quickly, eliminate critical influences and initiate improvements to in-house processes. Other potential areas where KorroPads may be used include incoming and outgoing goods inspection.

Dr Helga Leonhard is a test engineer at TÜV SÜD Chemie Service. Jens Lehmann is a research associates at Bundesanstalt für Materialforschung und-prüfung (BAM).

Please Login to comment
LEAVE A COMMENT