In-process radiographic monitoring of arc weld penetration

In-process radiographic monitoring of arc weld penetration

Working Group of Commission V ~[the International Institute of Welding (IIW) 39742 X-ray real-time imaging (radioscopy) for weld inspection: IIW 4th ...

160KB Sizes 0 Downloads 47 Views

Working Group of Commission V ~[the International Institute of Welding (IIW) 39742

X-ray real-time imaging (radioscopy) for weld inspection: IIW 4th progress report British Journal of Nondestructive Testing, Voi. 30, No. 6, pp. 400-40~ (Nov. 1988) Automated image interpretation in X-ray real-time inspection of welds is a complex field of pattern recognition. Real-time conditions and system characteristics require a powerful hardware configuration and special image analysis algorithms, but because of intensive investigations in the last few years, the automated image interpretation can now be regarded as a practical alternative to visual interpretation of the display screen image. Powerful image processing systems for this application arc now marketed by several manufacturers. 39631

Ooka, K.; Hirayama, K.; Senda, Y.

Study on the application of a contrastmeter examination

in radiographic

British Industrial and Scientific International Translation Service, London (United Kingdom), BISI-NF-69, 29 pp. (Jul. 1986). (Translated from Journal of Light Metals Welding, Vol. 24, No. 1, pp. 2-14, 1986) For radiographic tests, the use of a penetrameter and a contrast meter for indicating the quality of radiographs is specified in a Japanese Industrial Standard. Contrastmeters, on the other hand, are used only in Japan. They arc very useful for decisions on photographic conditions and the control of photographic work. Its use is restricted, under the Japanese industrial standard, to a thickness of under 20.0 mm. This study was carried out using a contrastmeter, to control image quality in these radiographic tests, without any restriction on the thickness of the sample. The quantitative relation between a penetrameter and a contrastmeter has been clarified on a basis of a radiographic test method and the classification of radiographs for aluminium welds (JIS Z 3105), structure and dimensions of a contrastmeter which can be used for samples measuring over 20.0 mm. 39618 Roye, W. X-ray testing of thermoplastic welding joints Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 2051-2059. Pergamon Press, 3173 pp. (1988) It is well known that X-ray testing of plastics and their welds is problematic. The difficulties arc discussed briefly and two ways which lead to improvements are demonstrated: the high current constant potential X-ray system and the newly developed Compton-backscatter technique. 39613

Calcagno, G.; Corsini, C.; Costa, G.

Conventional radiography: magnification tests - advantages and limitations Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 2000-2016. Pergamon Press, 3173 pp. (1988) The paper analyzes the special aspects of the magnification of conventional radiographs consisting of achieving radiographic images with very high definition (on a single emulsion film), subsequently magnified through a photographic technique on another radiographic film or on common photographic paper. This procedure may be usefully adopted for the solution of industrial radiographic investigations which are deemed very critical or at least difficult to resolve with standard radiographic techniques. Qualitative and quantitative results of tests performed at the N.D.T. Laboratory of the Italian Institute of Welding are reported. These results, correlated by means of special exposure charts for film magnification, set up the basis for the definition of a simple, yet reliable, test procedure. In addition, the paper illustrates some typical examples of test applications which, validate the above procedure. 39608

Arrondeau, P. Y.; Charbonnier. A.

Robot for real time radiographic inspection of circumferential welds with computer processing of the whole system Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 1575-1579. Pergamon Press, 3173 pp. (1988) This system is the result of two pieces of research work conducted jointly by lnstitut de Soudure and Intersub. The first is aimed at implementing and optimizing real time radiography in the field of welded constructions and developing a computerized system for real time inspection. The second is aimed at implementing this inspection procedure by robotizing the system. This research work led to the development of a robot for the non-destructive testing of underwater pipelines. 39607

Rose, P.; Builtjes, J. H.; Daum, W. ; Heidt, H.

digital data-base is more comfortable to use, contains more detailed inlormation about the radiographic parameters and can be used for radioscopy, qhc structure of the data- base and some typical applications will be demonstrated in this paper. 39601

Rokhlin, S.I.; Guu. A.C.

In-process radiographic monitoring of arc weld penetration Proceedings of the 16th Symposium on Nondestructive Evaluation, San Antonio, Texas (United States), 21-23 Apr. 1987. pp. 209-217. Nondestructive Testing Information Analysis Center, Texas, USA, In this study real-time radiography is used for in-process weld quality evaluation, with on-line testing of defect formation in the weld and welding process control. In this system, welding current can be remotely controlled during observation and computer processing of weld images. The experimental results are demonstrated for the submerged arc welding process. The welding pool is covered by a thick layer of the welding flux and, therefore, the poo ! is optically invisible. By using computer data of the gray levels of weld images and their histogram distributions, the three-dimensional shape of the submerged arc pool was studied. The depth of the welding pool can be measured in real time and can be used for weld tracking and process control. 3960(I

Eyerkuss, R.F.; Engelbart, R.W.

Automated radiographic inspection for circumferential welds Proceedings of the 16th Symposium on Nondestructive Evaluation, San Antonio, Texas (United States), 21-23 Apr. 1987. pp. 203-208. Nondestructive Testing Information Analysis Center, Texas, USA. Static radiography of complex welded aerospace components is costly in both time and materials. In an effort to reduce these costs and increase productivity, McDonnell Douglas Astronautics Company has developed a prototype automated radiography system for the inspection of circumferential welds. Following initial set-up of the hardware, and through the assistance of user friendly software, thc operator selects a technique which is pre-programmed and identified by part number. The exposure parameters, part manipulation, and film advancement are then automatically controlled throughout the inspection. Accuracy and repeatability of part motion can be maintained within a fraction of a degrce. All views of the weld appear on a single strip of five-inch wide roll film, eliminating the need for loading and unloading of cassettes. Preliminary trials indicate that with reduction of operator involvement, elimination of film cassette loading, and decreased processing time, an average manhour savings per part of 55 percent can be realized, depending upon size and geometry. 39533

Mudge, P.J.

NDT Research at the Welding Institute Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 1511-1519. Pergamon Press, 3173 pp. (1988) Through The Welding [nstitute's extensive contacts with all sectors thc fabrication industry a number of future industrial requirements for NDT have been identified. Examples are given of activities within the Institute's NDT Research Department which address these. 39466

Fry, D.A.; Pearsall, C.R.; Guu, A.C.

Design considerations for an industrial diode array digital radiographic system Transactions of the American Nuclear Society, Vol. 56, Supplement No. 3, p. 70-72 (Conference on Industrial and Radioisotope Measurement Applications, Pinehurst, North Carolina, 7-9 Sep. 1988) Work in the U.S.A. on the evaluation of line-scan diode array radiography (DADR) for a wide variety of industrial applications (welds, castings and electronic assemblies) is described. The advantages of digital overfilm radiography are discussed. Two prototype DADR systems have been constructed and evaluated and a computer model has been developed for performance prediction. This paper concentrates on the inspection of steel welds. The DADR system is described and results given. Image quality and scan rates will be improved in the future. 38882

Steinlndustrie

Tubular plate welds radiographic examination - in which two films are exposed for a long period compared to time to introduce and remove radioactive source European Patent No. 262,015 (30 Mar. 1988) 38878

CornNat Energia Atomica

Appts. for real-time automatic radiographic analysis of welds -has processor controlling positioning device on basis of data from TV camera to obtain optimal focusing European Patent No. 263,080 (6 Apr. 1988) 38645

Mudge, P.J.

Digital image data base for flaw classification in radiographs

NDT research at The Welding Institute

Proceedings of the 4th European Conference on Non-Destructive Testing, London (United Kingdom), 13-17 Sep. 1987. Vol. 3, pp. 1564-1567. Pergamon Press, 3173 pp. (1988) For the computer-aided estimation of weld radiographs an image-data- base was configurated and tested. In addition to the digitalized images the data-base includes a comprehensive documentation of the specimen, the imaging conditions and the weld defects. In comparison with available catalogues the

The Welding Institute, Cambridge (United Kingdom), 20 pp. (1987). Paper presented at the 4th European Conference on NDT, London, 13-18 Sep. 1987. Through The Welding Institute's extensive contacts with all sectors of the fabrication industry, a number of future industrial requirements for NDT have been identified. Examples arc given of activities within the Institute's NDT Research Department which address these requirements.

218

N DT & E International August 1991