Nondestructive-radiography

Luminescence IP s are fundamentally and theoretically utilizable for nondestructive testing if all of the recommended guidelines and operational recipes and appropriate systems are used. They are quite capable of producing image quality on a par with industrial radiography. 

P. Mclntire, ed., "Radiography and Radiation Testing," Nondestructive Testing Handbook, Vol. 3, 2nd ed.. The American Society for Nondestmctive Testing, Columbus, Ohio, 1985. 

Corrosion-fatigue cracks can be detected by nondestructive testing techniques such as magnetic particle inspection, radiography, ultrasonics, and dye penetrant. Corrosion-fatigue cracks may occur in numerous tubes simultaneously. Nondestructive testing of tubes at locations similar to those in which cracks are observed can be useftil. 

Identification. If accessible, defects from burnthrough may be visually identified as fused holes in the tube wall. Various nondestructive testing techniques, such as radiography and ultrasonics, may also detect this defect. The defect generally causes leakage soon after affected equipment is placed in service. 

Occasionally, corrosion of this type produces large cavities covered by a thin outer skin of weld metal (Fig. 15.5). Even close examinations of such sites under a low-power microscope may fail to reveal the cavities. Compare Figs. 15.6 and 15.7. Generally, such sites are detected either by fluid leakage or by nondestructive testing techniques such as radiography and ultrasonics. 

Identification. Slag inclusions will not be visually identifiable unless slag particles emerge at the weldment surfaces. Radiography, eddy-current testing, and ultrasonics are nondestructive testing techniques that can disclose slag inclusions. 

Identification. Weld-root cracks originate at the root of the weld and run longitudinally along the weld, perpendicularly to the base-metal surface and parallel to the axis of the weld. In general, they may be identified visually or by various nondestructive testing techniques such as radiography or ultrasonics. Failures from weld-root cracking may occur soon after start-up or after extended periods of successful service. 

Gross cracks may be visually observable. Nondestructive testing for the presence of cracks includes using dye penetrant, ultrasonics, and radiography. Determination of the cracking mechanism will require metallographic analysis. 

Nondestructive testing (NDT) is used to assess a component or structure during its operational lifetime. Radiography, ultrasonics, eddy currents, acoustic emissions, and other methods are used to detect and monitor flaws that develop during operation (Chapter 7). 

By contrast, the metals have so far found only limited application save for one important use in the field of nondestructive testing. With the proliferation of research reactors over the past decade, neutron radiography has become a practical tool in the aerospace, nuclear and engineering industries, yet without the availability of gadolinium and dysprosium in the form of thin foils, the technique would be severely restricted. 

Caitz, L. Nondestructive Testing Radiography, Ultrasonics, Liquid Penetrant, Magnetic Particle. Eddy Current, ASM International, Materials Park. OH, 1995 Cornua, R.D. Problem-Solving Surface Analysis Techniques. Advanced Materials Processes, 16 (December 1992). 

Nondestructive evaluation, also termed nondestructive testing or nondestructive inspection, is extensively used in weld testing (14). Nondestructive tests do no impair the serviceability of the material or component under stress. The most widely used tests for evaluation of welds are liquid penetrant, magnetic particle, ultrasonics, and radiography. Acoustic-emission tests are increasingly used. Nondestructive tests detect and characterize, in terms of size, shape, and location, the various types of weld discontinuities that can occur. 

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. 

The choice of the nondestructive technique used in the examination of the sample on hand also depends upon the complexity of the shape of the sample. The following order of the methods is in progressively increasing complexity of the shape of the sample to be examined acoustic microscopy, microwave method, eddy current, magnetic particle, X-ray radiography, ultrasonics, liquid penetrant and visual methods. 

Technical examination of objects coated with a protective covering derived from the sap of a shrubby tree produces information that can be used to determine the materials and methods of manufacture. This information sometimes indicates when and where the piece was made. This chapter is intended to present a brief review of the raw material urushi, and the history and study of its use. Analytical techniques have included atomic absorption spectroscopy, thin layer chromatography, differential thermal analysis, emission spectroscopy, x-ray radiography, and optical and scanning electron microscopy these methods and results are reviewed. In addition, new methods are reported, including the use of energy dispensive x-ray fluorescence, scanning photoacoustical microscopy, laser microprobe and nondestructive IR spectrophotometry. 

The soundness of welds is checked by visual inspection and by nondestructive testing (radiography). 

Green RE (1977) Flash radiography symp. proc. American Society for Nondestructive Testing, Columbus, Ohio 43221... 

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