36858 Anon. X-ray real time imaging for weld inspection: 2nd progress report Welding in the World, Vol.25, No. 1/2, pp. 10-14 (1987)

The first progress report, published in March 1986, formed an introduction to the subject of X-ray real-time imaging, which is a technique to produce a radiographic-type image on a television monitor, as an alternative to taking a radiograph on film. By digitizing the image into pixels, so that a computer can be used to "process" the image and to enhance its quality, large improvements in image quality are possible, which has led to claims that the XRTI image can be as good as that obtained on a conventional film radiograph. The potential advantages of XRTI in speed of inspection, reduction in operating costs, etc., are self-evident. This second progress report details further aspects of the method and the equipment required.

36721 Ford, J.; Hudgell, R.J. A final report on the performance achieved by non-destructive testing of defective butt welds in 50 mm thick Type 316 stainless steel United Kingdom Atomic Energy Authority, Risley Nuclear Power Development Laboratories, ND-R-1427(R), 40 pp. (Mar. 1987)

This report concludes a programme of work started approximately eight years ago to fabricate deliberately defective austenitie downhand welds in 50 mm thick type 316 plate and then to examine them non- destructively under ideal laboratory conditions. After completing and reporting the Non-Destructive Testing (NDT), the specimens were subjected to detailed metallography to locate, identify and size all the planned and unplanned flaws in the welds. The report gives the final analysis of this exercise on the relative merits of X- radiography, pulse echo ultrasonics and the time-of-flight technique for the detection, location and sizing of weld flaws.

36598 Anon X-ray real-time imaging for weld inspection: l lW 2nd progress report British Journal of Nondestructive Testing, Vol. 29, No. 1, pp. 22-24 (Jan. 1987)

The first progress report, published in March 1986, formed an introduction to the subject of X-ray real-time imaging, which is a technique to produce a radiographic-type image on a television monitor, as an alternative to taking a radiograph on film. By digitising the image into pixels, so that a computer can be used to "process" the image and to enhance its quality, large improvements in image quality are possible, which has led to claims that the XRTI image can be as good as that obtained on a conventional film radiograph. The potential advantages of XRTI in speed of inspection, reduction in operating costs, etc are self-evident. This second progress report details further aspects of the method and the equipment required.

36589 Daum, W.; Rose, P.; Heidt, H.; Built]es, J.H. Automatic recognition of weld defects in x-ray inspection British Journal of Nondestructive Testing, Vol. 29, No. 2, pp. 79-81 (Mat. 1987)

The main basis for automatic image analysis in X-ray inspection of welds is a segmentation algorithm which detects and marks the defects reliably in the radiograph. The problem for the defect segmentation is that in many cases, the defect representation is superimposed on other image structures due to the shape of the welding seam. By a sophisticated background modelling technique it is nevertheless possible to achieve automatic defect recognition. A comparison between a visual and an automatic evaluation shows the efficiency of this method.

36588 Johnson, J.A.; Carlson, N.M.; Kunerth, D.C. Feasibility tests of observing weld pools using real-time radiography EG and G Idaho, Inc., Idaho Falls (United States), EGG-SD-7338, DE87-000461, 19pp. (Jut. 1986)

This report describes the preliminary analytic and experimental work conducted at the Idaho National Engineering Laboratory (INEL) to determine the feasibility of using real-time radiography to observe the formation and properties of molten weld pools. The calculations show that the expected density changes in steel due to the weld pool could be observable in ideal circumstances. Subsequent experiments, using available equipment without any special adaptations, confirmed the analytic results. The following sections give a short summary of the important factors in standard radiography, the preliminary analysis for weld pool imaging, a discussion of the experimental technique and results, and a summary and recommendations.

36459 Kohutek, T.L. An evaluation of photon tomography and other nondestructive testing methods for the inspection of bridge weldments Dissertation Abstracts International, Vol. 47, No. 5, p. 2086 (Nov. 1986)

The computerized tomography (CT or CAT-scan) imaging process is examined as an alternative technique for the nondestructive evaluation (NDE) of weldments. An extensive NDE test program including radiographic testing (RT), ultrasonic testing (UT), and CT was conducted on machine-flawed specimens (phantoms), intentionally flawed T and butt welds, and submerged arc welds from an in-service bridge. Destructive examinations (DE) were also performed on certain weldments to verify the results of the NDE. It was found that CT has a higher sensitivity index for detecting planar defects than the most sensitive RT, but lower than that of UT for defects less than 0.5 in. in length. In addition, CT provides data about the defect geometry required to evaluate defect severity that cannot be obtained by standard UT and RT. These results indicate that CT is a viable means of weld inspection when used in conjunction with UT and RT.

Each entry in NDT Abstracts consists of the serial number in the National NDT Centre Information Store for identification purposes; the title of the paper, book or report; the name of the author; the name of the source journal or document and the abstracts. Where necessary, author 's names and the title of foreign journals have been transliterated into the Latin alphabet according to British Standard BS 2979:1958.

Availability of Publications

Most papers listed may be obtained as loans or copies via local library or direct from Loans Department, British Library Document Supply Centre, Boston Spa, Wetherby, Yorkshire LS23 7BQ. Details of the British Lending Library's UK and International' Services may b e obtained from The Director, British Library Lending Division. Technical reports are also available from the Loans Department of the British Lending Library and in the USA from the National Technical

Information Service, US Department of Commerce, Springfield, Virginia 22151, USA. British and foreign standards can be obtained from Sales Department, British Standards Institution, 101 Pentonville Road, London N1 9ND; and British and foreign patents from the Patents Office Sales Branch, Block C, Station Square House, St Mary Cray, Orpington, Kent BR5 3RD.

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All entries are indexed in a computerized retrieval system, located at Harwell, which allows rapid searching of information relevant to any particular inspection problem. This service is available to both UK and overseas organizations through the National NDT Centre's Qualtis Subscription Scheme - further details are available from Phil Lawrence on Abingdon (0235) 433391.

© 1991 United Kingdom Atomic Energy Authority

220 NDT& E International August 1991