Corrosion detection

Fig. 1 Shematic of eddy current probe for corrosion detection.

Fig. 2 Conventional flat-bottom hole calibration standard for corrosion detection.

F. Schur, ]. Rohman, T.W. Guettinger Corrosion Detection. A new Approach Using Eddy Currents. ATA 1995 NDT FORUM Hartford, Connecticut, USA September 26-28, 1995. 

Examples will cover maintenance inspection such as corrosion detection in piping and tanks, but also routine weld inspection. The need for acceptance criteria for weld defects adapted for modern NDT techniques will be highlighted, because these form (in many cases) the key to benefit. 

LORUS is also used for inspection of piping that has been on supports or sleepers for some time, to see whether corrosion has developed at the contact points. But the technique can also be used for corrosion detection under insulation, inspection of pipelines at dike and road crossings, nozzle reinforcement pads or craek detection in suspension systems for railway cars. 

Since the reliability of gas turbines in the power industry has been lower than desired in recent years because of hot-corrosion problems, techniques have been developed to detect and control the parameters that cause these problems. By monitoring the water content and corrosive contaminant in the fuel line, any changes in fuel quality can be noted and corrective measures initiated. The concept here is that Na contaminants in the fuel are caused from external sources such as seawater thus, by monitoring water content, Na content is automatically being monitored. This on-line technique is adequate for lighter distillate fuels. For heavier fuels, a more complete analysis of the fuel should be carried out at least once a month using the batch-type system. The data should be input directly to the computer. The water and corrosion detecting systems also operate in conjunction with the batch analysis for the heavier fuels. 

J. W. Boivin, J. W. Costerton, E. J. Laishley, and R. Bryant. A new rapid test for microbial corrosion detection and biocide evaluation. In Proceedings Volume, pages 537-547. 2nd Inst Gas Technol Gas, Oil, Coal, Environ Biotechnol Int Symp (New Orleans, LA, 12/11-12/13), 1989. 

Corrosion detection plays an important role in any corrosion control program. Most of the methods employ nondestructive test methods and include hydrogen evaluation, radiography, dynamic pressure, corrosion probes, strain gauges and eddy current measurements. Of these, the methods employed in cooling tower practice are hydrogen evaluation and corrosion probes. 

Periodic inspection of equipment or plant for detection and monitoring corrosion should be followed by a written report, detailing all the observations and the necessary actions to be taken in future maintenance so that unexpected premature failures can be avoided. It is also necessary that all personnel involved are aware of the observations in the periodic inspection report on corrosion detection and monitoring in order to avoid future premature failures. 

Amino sugars and amino alcohols Amino sugars Hybrid analyzer non-corrosive detection (cf., text) Dawson and Mopper [229]... 

PULSE-ECHO TECHNIQUES - Corrosion detecting processes which, by recording the action of ultrasonic waves artificially introduced into production structures, can determine metal thickness and detect flaws. 

Corrosion Detection Using Intelligent Pigs, Corrosion Information Compilation Series, Pipeline Corrosion, NACE International, Houston, TX, 1999. 

Additional corrosion detection equipment, deluge systems, and fire pumps were recommended, which would cost 600,000. Because of the exceptionally high retentions (deductibles) in the insurance program, the cost of fire protection improvements would not be offset by insurance cost savings. 

Uronic acids have been separated on anion-exchange resins in a simple system involving no elevated column temperatures or changes in buffer composition. A highly sensitive non-corrosive detection reagent, 2,2 -bis-cinchoninate, which did not react with amino-acids or neutral monosaccharides, was employed. 

Organic sorbents have the disadvantage of charring with corrosive detection reagents. 

Another successful use of the F-map system in adhesive bond inspection is demonstrated with the in-service inspection problem of corrosion detection. Corrosive attack of the substrate material first reduces the adhesive strength of the bond metal interface and is then followed by total debonding. A sample result is presented in Figure 21. 

Komorowski JP, Krishnakumar S, Gould RW, Bellinger NC, Karpala F, Hageniers OL. Double pass retroreflection for corrosion detection in aircrafi structures. Materials Evaluation 1996 54 80-6. 

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