Weld penetration control with radiographic feedback on weld pool depression

Weld penetration control with radiographic feedback on weld pool depression

N DT Abstracts Repair of tools for drop forges can save considerable costs. Therefore, in a joint project consisting of partners experienced in weldin...

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N DT Abstracts Repair of tools for drop forges can save considerable costs. Therefore, in a joint project consisting of partners experienced in welding and partners from X-ray inspection, the possibility of automizing this process using computer-controlled manipulation systems has been investigated. Software for control and defect evaluation has been written. This paper is related to the real time X-ray inspection part of the project.

Bo, W.; Xiao-jun, L. Three-dimensions flaw detection for the welded seams of

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p r e s s u r e vessels International Journal of Pressure Vessels and Piping, Vol. 48, No. 3, pp. 331-341 (1991) This article deals with the three-dimensional analysis of internal flaws occurring in the welded seams of pressure vessels so as to determine the real location of the defects. For this purpose stereoscopic twin radiographs were used. Owing to the fact that r.- tiographs are taken with films in circular form whereas the films have to be assessed in the flat condition, it is necessary to establish the relevant analytic relation between circular and the flat film. To this end some equations were first established for the image points of the assumed fiat film and that of the circular film, leading to the relevant formulae for ascertaining the spacial point location of the defect in the welded seam. Defects of different locations bring about different photocouple-points. The real location of the defect can be determined through its coordinates, Zsub A/and Y obtained through film observation and calculation.

Bjorkholm, P.J.; Parker, R.; Johnson, M. Design and application of a digital radiographic weld inspection system 47440

NDE: The Next Decade and Beyond. 1990 ASNT Spring Conference, San Antonio, Texas (United States), 19-23 Mar. 1990. pp. 187-189. ASNT (1990) American Science and Engineering (AE&E) is now designing and building a digital weld inspection system under contract to Boeing Aerospace Corporation. The system will be used to inspect welds on the space station. The system is designed to image 1080" of continuous weld with a spatial resolution of 8 lp/mm and a sensitivity of 2-1t. The system consists of three basic components: the X-ray generation system, the X- ray detection system, and the data acquisition and display system. 46929 Nockemann, C.; Heidt, H.; Thomsen, N. R O C study of inspection performance in radiographic testing of

welded joints Welding in the World, Vol. 29, No. 5-6, pp. 108-118 (1991) The complexity of modem NDT equipment as well as the demand for high reliability in several industries makes it necessary to have a tool which can rapidly asses different NDT techniques and devices. For cost benefit considerations a measure of accuracy has to include not only the amount of correctly detected defects but also the corresponding amount of false indications. In order to satisfy a variety of safety demands this ratio of true and false indications must be known for a wide range of the decision criteria; the signal or defect size which is counted as a real signal; all values smaller are counted as noise. All this information will be provided by only one receiver operating characteristic (ROC) study of inspection data using the rating- confidence method. An expanded ROC version also yields an assessment of the accuracy of the defect classification and of the correctness of the indicated defect importance.

threshold levels, welding conditions are automatically adjusted to maintain required weld penetration.

Shub, B.M.; Chibirova, L.G.; Kass, M.A. Electroradiographic inspection of the quality of welded joints in pipes 45429

V.E. Riecansky, Technical Translations, VR-4353 2 pp. (1990) 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 Atomkntiomash Scientific and Production Organisation for mechanisation of ERG inspection of the quality of welded joints in pipes of the heating surfaces directly in the welding line is described.

Potapov, V.N.; Belyi, N.G.; Grom, V.S. Increasing the contrast of defect images in radiation inspection of welded joints 45428

V.E. Riecansky, Technical Translations, VR-4340 3 pp. (1990) 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.

Anon. Summary report: X - r a y real time (radioscopy) for weld inspection

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Welding in the World, Vol. 28, No. 5-6, pp. 74-83 (1990) This report summarizes four published progress reports detailing the equipment, methods and application of real time radiography (radioscopy) for the inspection of welds. Radioscopy produces an image of the weld on a television display monitor screen and methods of image enhancement are detailed. This method of inspection has developed to be a competitor to radiography on film and has the possibility to develop further into an automated inspection method, using automatic image interpretation. Permanent records with no loss in image quality are available if required, using a laser and a rigid optical disc. 44888 Lloyd, J.F. A review of computer-aided interpretation technology for the

evaluation of radiographs of aluminum welds Proceedings of the Conference on Nondestructive Evaluation for Aerospace Requirements, Huntsville Alabama (United States), 26-27 Aug. 1987. pp. 63-78, Edited by G.L. Workman, Gordon and Breach Science Publishers 1989 ISBN 2881243053 Hundreds of miles of radiographic information are evaluated, documented and archived annually. In many instances, there are serious considerations in terms of interpreter fatigue, subjectivity and limited archival space. High resolution cameras, digital image processing, and mass digital data storage offer interesting possibilities for improving the industrial radiographic process. This paper will present a review of computer aided radiographic interpretation technology in terms of how it could be used to enhance the radiographic interpretation process in evaluating radiographs of aluminum welds.

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44198 Taylor, R.G. NDT of electron beam welded joints (micro-focus and real time

Welding Journal, Vol. 70, No. 3, pp. 61-65 (Mar. 1991) The use of real-time radiography, radioscopy using X-rays to detect internal flaws in welded joints is described. Radioscopy allows the part under inspection to be moved, enlargement or reduction of the image, image-enhancement techniques and the ability to automate the inspection sequence. The fundamentals of radioscopy and the opportunities it offers in process control are outlined. The basic principles of the geometric configuration of X-ray source, part to be inspected and imaging system are discussed.

X-ray) Advanced Joining of Aerospace Metallic Materials, AGARD-CP398, 4 pp. (Jul. 1986) The introduction of electron beam welding (EBW) into the aero engine industry in the early 1960's has presented many new problems for nondestructive testing (NDT). Recently, significant developments have taken place which has enabled micro-focus X-ray techniques to be used in place of conventional X-ray on EBW and this has resulted in a considerable improvement in defect detection capabilities. An additional bonus has been the reduction in inspection costs and an improvement in productivity.

45738 Guu, A.C.; Rokhlin, S.L W e l d penetration control with radiographic feedback on weld

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Schlieper, F~I.; Green, M. Radioscopy offers flexibility, speed in weld inspection

pool depression Review of Progress in Quantitative Nondestructive Evaluation, Brunswick, Maine (United States), 23-28 Jul. 1989. Vol. 9B, pp. 1973- 1980. Edited by D.O. Thompson and D.E. Chimenti. Plenum Press (1990) In this paper, control of weld penetration is accomplished by use of radiographic information on weld pool depression. During weld control based on comparison of the measured depressed pool depth and width with

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Potapov, V.N.; Belyi, N.G.; Groin, V.S. On increasing the contrast of flaw images in the radiographic inspection of welds (In Russian)

Tekhnicheskaya Diagnostika i Nerazrushayushchii Kontrol, No. 2, pp. 11- 14 (1989) Using the method of a recent application of the theory of small perturbations, quantatitive data on the influence of slit diaphragming on the contrast of flaw images during the radiographic inspection of welds have been obtained. Experimental results supporting the theoretical data are presented.