CORROSION NEWS - DECEMBER 2000

Detection of Hidden Corrosion in Aircraft Structures: Developments Involving the Pulsed Eddy Current Method

Feds Sue Colonial over Oil Spills from Pipeline Involving Alledged Corrosion

Corrosion Research Reaps Reward

Fighting Rust in Tool Drawers

India: New Technique to Solve Metallurgical Problems

Australian Patrol Boats Beached by Corrosion

Millennium Plastics to Launch Solplax Vapor Corrosion Inhibitor Product Line with European Distribution Partners

Cargo Tanks Stainless Steel Holds the Key to Easier Pristine Restoration

Using Thermography to Characterize Damage from Corrosion

FAA Proposes Airworthiness Directive for All A319, A320 and A321 Aircraft

New Erosion-corrosion Theories

DETECTION OF HIDDEN CORROSION IN AIRCRAFT STRUCTURES: DEVELOPMENTS INVOLVING THE PULSED EDDY CURRENT METHOD.

The Canadian Defense and Civil Institute of Environmental Medicine has investigated the pulsed eddy current (PEC) method as an approach that addresses the requirements for accurately characterizing hidden corrosion in aircraft structures. It examines the potential of PEC for detecting and characterizing corrosion in thin-skin fuselage lap-splices. It describes the PEC detection system developed at the Air Vehicle Research Detachment, and the results of PEC experiments performed in the laboratory and on in-service multi-layered specimens.(InfoTeamMA@aol.com)

FEDS SUE COLONIAL OVER OIL SPILLS FROM PIPELINE INVOLVING ALLEDGED CORROSION

The Justice Department on Tuesday filed a massive lawsuit against the Atlanta-based Colonial Pipeline Co. (the worlds largest pipeline company), alleging that the firm's 5,300-mile pipeline has caused a number of disastrous spills.

The lawsuit, filed on behalf of the U.S. Environmental Protection Agency, contends that pipeline corrosion, mechanical damage and operator error have resulted in the numerous spills during the past 20 years. In addition to Georgia, major spills from the pipeline have occurred in Louisiana, Alabama, Tennessee, South Carolina, North Carolina, Maryland, Virginia and New Jersey.

Colonial officials said Tuesday they were "disappointed" that the lawsuit was filed because they have been working with the Justice Department and other federal agencies to find resolutions to the pipeline problems. The company in an earlier settlement agreed to pay more than $ 13.5 million in fines.

In addition, the lawsuit asks the court to order Colonial to take several steps to prevent future spills: Investigate the depth and condition of the dirt or other material that covers the buried pipeline and take action to address exposed and shallow pipe. Inspect the pipeline for defects such as corrosion and cracks, and make necessary repairs. Upgrade the pipeline's leak detection strategy and system.

Adapted from story from The Atlanta Constitution

CORROSION RESEARCH REAPS REWARD  top

A University of Utah scientist, Mike Free, and four other Utahns recently were named among 409 outstanding scientists and engineers nationally to receive Faculty Early Career Development awards. The award, the National Science Foundation's most prestigious honor for junior faculty members, supports research projects for up to five years.

"Corrosion costs us in the United States more than $100 billion each year in various forms," Free noted in a Deseret News interview.

Free’s work is "Understanding and Improving Corrosion Minimization Using Surfactants and Education." He has been studying two approaches to reducing the damage caused by corrosion. The first is to educate people about the best approaches to control corrosion using existing techniques. His other approach is to discover materials that will fend off corrosion through corrosion inhibitors. Most of this work focuses on steel, although aluminum and stainless steel.

In his experiment, Free and student assistants use surfactants to form protective layers on metals. They track the absorption of these surfactant molecules on metal surfaces," testing how well each type protects the metal beneath. So, far, they have found some surfactants that will give about 90 percent reduction in the rate of general steel corrosion, depending on the environment. Surprisingly, the studies have shown that some materials actually speed up corrosion. E-MAIL: bau@desnews.com   The Deseret News (Salt Lake City, UT)

FIGHTING RUST IN TOOL DRAWERS  top

Hand tools stored in workbench drawers often rust, especially if the workbench is in the basement, garage or back-yard shed. One way to fight corrosion is to line the drawer bottoms with a piece of carpeting cut from a remnant or product sample that's been sprayed with a generous coating of lubricant. The carpet will help keep the tools from rolling around and banging into each other, scratching the finishes and dulling sharp edges, while the lubricant will prevent rust. Remove the tools at least once every two months and respray the carpeting. Chicago Tribune Company  

INDIA: NEW TECHNIQUE TO SOLVE METALLURGICAL PROBLEMS  top

The International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), an autonomous Research and Development Centre of the Department of Science and Technology, has transferred a new technique of solving problems relating to severe wear and tear, corrosion, erosion and high temperature, to Messrs Sai Surface Coating Technologies, Hyderabad.

The thermal spray coating facility called Detonation Spray Coating was today inaugurated by Mr Y.S.Rajan, Scientific Secretary to the Principal Scientific Advisor to the Government of India. About 50 per cent of total project cost was funded by the Technology Information, Forecasting and Assessment Council. The facility is being established at the ARCI Technology Park, Balapur. Detonation Spray Coatings have been found to consistently outperform those deposited by competing thermal spray techniques. Proven areas where these can be applied include serospace, automotive, chemical, electronics, glass and marine. Dr G. Sundararajan, Director, ARCI, presided over the function while Mr N.Nageswara Rao, Managing Partner, Sai Surface Coating Technologies, welcomed. Asia Intelligence Wire 

AUSTRALIAN PATROL BOATS BEACHED BY CORROSION  top

The Royal Australian Navy (RAN) has been forced to withdraw from service two Fremantle-class patrol boats because of excessive structural deterioration and heavy corrosion. An estimated A$1.4 million (US$750,000) is needed to rectify the problems before the vessels will be fit to return to service. Jane's Defense Weekly

MILLENNIUM PLASTICS TO LAUNCH SOLPLAX VAPOR CORROSION INHIBITOR PRODUCT LINE WITH EUROPEAN DISTRIBUTION PARTNERS  top

Millennium Plastics Corporation (OTCBB:MPCO) announced today that Solplax Limited of Ireland, a wholly owned subsidiary of Millennium Plastics, is preparing to launch its range of Solplax(TM) corrosion protection and vapor corrosion inhibitor (VCI) packaging products with its European distribution partner, Papiers Paviot of France (www.papiers-paviot.fr/org/).

Paviot is a market leader in sales and distribution of corrosion protection packaging products within France and surrounding countries, and has embraced the Solplax(TM) product as a major advance in the industry. Paviot's main corrosion protection products include VCI papers and VCI polyethylene films, which are sold to automotive industry leaders such as Peugeot and Renault and other component manufacturers as well as the steel and machinery industry. http://www.millenniumpolymers.com   Business Wire

CARGO TANKS STAINLESS STEEL HOLDS THE KEY TO EASIER PRISTINE RESTORATION  top

The common causes of corrosion damage in stainless cargo tanks are concentrated to either the carriage of a small number of dangerous or to inappropriate seawater cleaning procedures. Off-spec cargoes may also, from time to time, contribute to the number of reported corrosion. The most common corrosion problems in chemical tankers are pitting attack and uniform corrosion attack. Conditions that cause pitting attack will also usually cause crevice corrosion attack on pumps and other internals where crevices are present.

The first priority when damage is discovered is always to try to ensure that any damage that has already occurred does not spread further. This naturally means that the loading of any corrosive cargo must be avoided at all costs. Acids and chloride containing cargoes are not permitted and seawater cleaning may no longer be used.

Any cleaning to be done before repairs have been performed must be done with fresh water. The use of passivation with nitric acid that sometimes occur as a more or less automatic response to any presence of rust in cargo tanks should be avoided. If pitting attack has occurred then there are occluded pits and small holes in the material acid will seep into the pits during the passivation treatment but will not be removed by the freshwater rinse at the end of the treatment. The addition of acid to the chloride containing solution inside the pits will make the conditions inside the pits very much more aggressive and consequently make the damage more severe.

All repairs, regardless of whether it is corrosion damage or mechanical damage that is to be repaired, must take the effects on corrosion resistance into consideration.

In contrast to a coated tank where the corrosion resistance is added on top of the metal by a separate coating layer the corrosion resistance of the stainless steel is built into the surface of the metal itself. This means that the surface integrity of the metal is vital. Certain types of contamination of the stainless surface during repairs may result in an irreversible lowering of the corrosion resistance. Especially the combination of oil or grease and heat from welding or flame straightening may result in carbon pick-up and damage to the corrosion resistance of the tank surface. Cleanliness during repairs is therefore of utmost importance.

Although repairing cargo tanks is something that every chemical tanker operator wishes to avoid it also a way of securing the continued use of valuable equipment. If properly performed, using proper procedures, repairs can ensure that a damaged cargo tank can be returned to service without an restrictions for the future use of the tank.

In this respect stainless steel offers the possibility to rather easily restore the cargo tanks of a chemical tanker to an almost pristine and to obtain many more years of service from the vessel when things go wrong.

Bela Leffler is an engineering physicist who is quality control and technical service manager within Avesta Sheffield AB, Sweden. http://avestasheffield.com

USING THERMOGRAPHY TO CHARACTERIZE DAMAGE FROM CORROSION  top

This Naval Air Warfare Center Aircraft Division has prepared a report that addresses thermography as a viable NDE (nondestructive evaluation) technique for the characterization of corrosion in metallic materials. Thermography is a rapid noncontact wide-area inspection technique that is easy to interpret and not significantly sensitive to material curvature. A portable thermography system has been constructed and characterized for the sensitivity of the technique. The results are presented in the report.(InfoTeamMA@aol.com)

FAA PROPOSES AIRWORTHINESS DIRECTIVE FOR ALL A319, A320 AND A321 AIRCRAFT  top

The US Federal Aviation Administration (FAA) has issued a document that proposes the adoption of a new airworthiness directive (AD) that is applicable to all Airbus Model A319, A320 and A321 series aircraft.
The proposal would require a revision of the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to incorporate service life limits for certain items and inspections to detect fatigue cracking, accidental damage or corrosion in certain structures. Comments about this proposal must be received by 4 December 2000. (aii.feedback@m2.com)

NEW EROSION-CORROSION THEORIES.  top

A (University of Florida) reports addresses the erosion-corrosion of copper and copper-nickel alloys in synthetic seawater, which is investigated using an impinging jet. Video microscopy, corrosion potential monitoring, and impedance spectroscopy, are used to investigate the state of the system and the reactivity of the electrode surface. Shear-induced removal of salt films is observed, and is found to be associated with significant increases in surface reactivity. Direct shear-induced removal of oxide films, however, is not observed. Nevertheless, the protective oxide layer shows sensitivity in passively aerated seawater to large fluid velocities and to small perturbations in potential. The films are stable, under all conditions tested. in continuously aerated seawater. The work supports the argument that localized corrosion of copper alloys is caused by galvanic coupling between different regions of a metal coupon. Thus, cathodic protection may be used to prevent such corrosion.(InfoTeamMA@aol.com)