When ancient Chinese urns, made of cast bronze, were examined, at the Cincinnati Art Museum in Ohio, using computed tomography (CT) a number of surprises were found. Repairs to the legs, weld repair and extreme variations in the porosity of the bronze were all noted. This use of up-to-the-minute nondestructive technology has inspired a respect for Chinese metal workers in todays scientists.

44181 Potapov, V.N.; Belyi, N.G.; Grom, V.S. Increasing the contrast of defect images in radiation inspection of welded joints Technical Diagnostics and Nondestruct ive Testing, Vol. 1, No. 2, pp. 74-76 (Apr . - Jun . 1989)

The method of consecutive application of the theory of small perturbations was used to obtain quantitative data on the effect of slit stopping down in radiation inspection of welded joints on the contrast of defect images. The experimental results which confirm the calculated data are presented.

44176 Shub, B.M.; Chibirova, L.G.; Kass, M.A. Electroradiographic inspection of the quality of welded joints in pipes Technical Diagnostics and Nondestruct ive Testing, Vol. 1, No. 2, pp. 124-125 (Apr . - Jun . 1989)

The authors describe the method of electroradiographic (ERG) inspection of the quality of welded joints in pipes of heating surfaces which does not require X-ray film and improves the productivity of inspection. Equipment developed by the Atomkotiomash Scientific and Production Organisation for mechanisa- tion of ERG inspection of the quality of welded joints in pipes of the heating surfaces directly in the welding line is described.

44173 Gayer, A.; Saya, A.; Shiloh, A. Automatic recognition of welding defects in real-time radiography N D T Internat ional , Vol. 23, No. 3, pp. 131-136 (Jun. 1990)

This paper describes a real-time radiography configuration for the automatic inspection of welds. The optimal geometrical geometrical imaging configuration is evaluated and discussed in relation to conventional film radiography. For the automatic inspection of X-ray images, a two-step analysis was adopted: a fast search for defective regions, followed by fine identification and location of defects. Two different algorithms, based on the relative irregular behaviour of a defect, were developed for the fast search procedure. The second step, fine identification, can be achieved by a sequential similarity detection algorithm or by a thresholding algorithm. The different methods were applied to various X-ray images of welds and the automatic inspection was evaluated and compared with visual inspection.

44089 Kulikov, V.P.; Garyshev, A.P. Identifying reasons for rejects caused by operations and equipment in a multistage technological process Technical Diagnostics and Nondestruct ive Testing, Vol. 1, No. 2, pp. 131-134 (Apr . - Jun . 1989)

The authors describe the development of mathematical software, algorithms and computer programs for processing information on the quality of welding pipes for transmission gas pipelines. Processing gives the data on the quality of operation of every equipment and welder from the total information on the quality of all consecutive operations provided by X-ray inspection at the end of the flow line. The results can be used for any technological process which includes several consecutive stages with parallel working areas and inspection of quality at the end of the flow line.

43986 Parmee, R. X-ray give in-depth inspection Sensor Review, Vol. 10, No. 2, pp. 84-86 (Apr. 1990)

This paper explains the generation, detection and widespread use of X- rays as an inspection tool where their penetration into soft materials may be used to advantage. Recently, X-ray inspection systems frequently employ automatic image processing and the preparation necessary for this are outlined. Various applications to food, weld and baggage inspection and in the electronics and engineering component industries are discussed.

43984 Rokhlin, S.I.; Guu, A.C. Computerized radiographic sensing and control of an arc welding process Welding Journal , Vol. 69, No. 3, pp. 83s-97s (Mar. 1990)

The paper summarizes an effort in which real-time radiography was implemented for on-line arc welding process study and control. X-ray penetrating radiation was used for volume observation in the welding pool and the heat-affected zone during the weld process. The advantages of such a technique are on-line detection and monitoring of of defect formation in the weld and capability to study metal fusion and filler metal/base metal interaction and metal transfer in the welding pool. This technique may also be used for postservice, real- time remote testing of weld quality.

43982 Rohkhlin, S.I.; Guu, A.C.; Cho, K. Closed-loop radiographic process control of arc welding Proceedings of the 15th Annua l Review of Progress in Quanti ta t ive Nondestruct ive Evaluat ion, La Jolla, California (USA) , 31 Jul. - 5 Aug. 1988. Vol. 8B, pp. 2173-2180. Edited by D.O. T hompson and D.E. Chimenti . P lenum Press (1989). ISBN 0-306-43209-9.

In this paper, the implementation of real-time radiography for in- process control of arc welding is discussed. X-ray penetrating radiation is used for volume observation in the welding pool and the heat-affected zone during the

weld process. The advantages of such a technique are on-line testing of defect formation in the weld and the availability of this information for feedback control of weld quality.

4398O Lloyd, J.F. Review of computer aided interpretation technology for the evaluation of radiographs of aluminum welds Martin Mariet ta Aerospace , New Orleans, Louisiana, (Uni ted States), N89-25312/4/GAR, 21pp. (Aug. 1987)

High resolution cameras, digital image processing, and mass digital data storage offer interesting possibilities for improving the industrial radiographic process. A review is presented of computer aided radiographic interpretation technology in terms of how it could be used to enhance the radiographic interpretation technology in terms of how it could be used to enhance the radiographic interpretation process in evaluating radiographs of aluminum welds.

43979 Murray, S.H. Computed tomography used in weld inspections at NASA Welding Journal , Vol. 69, No. 2, pp. 33-39 (Feb. 1990)

As a technique, computed tomography (CT) has may applications. This paper describes how the valuable nondestructive evaluation (NDE) tool was used to inspect welds on critical ground support equipment for the space shuttle at the Kennedy Space Center, as other NDE techniques proved unsuccessful. Some welded-end hydraulic accumulators were thought to contain fatigue cracks, which might lead to high-velocity or high-volume leakage of hydraulic fluids. C.T. was successfully used to identify three levels of fatigue defects.

43900 DeNale, R.; Lebowitz, C. A comparison of ultrasonics and radiography for weld inspection Proceedings of the 15th Annua l Review of Progress in Quanti ta t ive Nondestructive Evaluat ion, La Jolla, California (USA) , 31 Jul. - 5 Aug. 1988. Vol. 8B, pp. 2003-2010. Edited by D .O. T h o m p s o n and D.E. Chimenti . P lenum Press (1989). ISBN 0-306-43209-9.

Since the 1940's, the accepted inspection method for structural welds in the U.S. Navy has been radiography (RT). Ultrasonics (UT), has been applied in other industries such as the nuclear power industry and off- shore oil platforms for inspection of welds. Literature indicates that there is rarely a good correlation of ultrasonic and radiographic weld discontinuity detection capabilities. This is due to the difference in operating principles of radiography and ultrasonics (absorption versus reflection, respectively) and therefore different capacities for detecting certain types of discontinuities. The objective of this program is to determine if structural welds may be ultrasonically inspected with repeatability and reliability comparable to that currently obtained with radiographic inspection.

43201 Reynolds, F.E. The introduction of real-time radiography for the inspection of butt welds in offshore pipelines Proceedings of the Sixteenth Annua l Offshore Technology Con- ference, Hous ton , Texas (USA) , 7-9 May 1984, Vol. 2, pp. 295-302

Real time radiography may significantly reduce the costs and efforts, improve the reliability, and eliminate some subjectivity arising from the conventional film radiographic inspection of butt welds in offshore pipeline production. This paper describes this state of the art technology and discusses its introduction to the production line of transitional pipe laying barges.

43197 Yah, L. Control of the K-value for radiographic inspection of welded joints British Journal of Non-Destruct ive Testing, Vol. 32, No. 2, pp. 63-68 (Feb. 1990)

The significance of controlling the penetrated thickness ratio, K and the maximum thickness ratio Kma x in the radiographic inspection of welding joints is discussed. Taking typical radiographic applications as examples, the paper presents methods for controlling values of K and Kma x as well as practical applications. These methods have been incorporated in the new Chinese National Standard GB- 3323-87.

42809 Boving, K.G. (ed) NDE Handbook, Non-destructive examination methods for condition monitoring Butterworths, 418pp. (1989) ISBN 040804392X

This handbook of nondestructive evaluation (NDE) produced in Denmark, describes the applications and limitations of NDE techniques to condition monitoring, as fixed by national and international standards. In condition monitoring, the choice of NDE method depends on material deterioration in a given environment, and often several methods are combined. Various authors describe a wide range of NDE techniques which can be used on their own or in combination to effect condition monitoring in the mechanical engineering and processing industry.

42676 Lo Vavlo, E.; Masnata, A. Automatic detection of weld defects in radioscopy Proceedings of the International Conference on Monitoring, Surveil- lance and Predictive Maintenance of Plants and Structures, Taormina - Giardini Naxos, Sicily (Italy), 15-18 Oct. 1989, pp. 584-590. Italian Society for Nondestruct ive Testing

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