INDUSTRIAL RADIOGRAPHY

Transcription

1 1. Module Details Module name Nominal duration INDUSTRIAL RADIOGRAPHY 3 modules It is anticipated that a learner holding the prescribed entry level skills will achieve the module purpose in 105 to 120 hours Module Codes Discipline Code EA610 Non-destructive testing (Code to be allocated) 2. Module Purpose To provide learners with knowledge of the principles, procedures and applications of radiographic testing, to develop the competency to undertake radiographic testing of materials in accordance with the requirements of national and international codes and specifications, and to interpret the results of such tests 3. Prerequisites Radiography and Radiation Safety - EA Relationship to competency standards This module, in association with the module Radiography and Radiation Safety, meets the training requirements for Level 2 qualification in radiographic testing under AS "Nondestructive Testing - Qualification and Certification of Personnel - General Engineering" and AS "Non-Destructive Testing - Qualification and Registration of Personnel - Aerospace". Currently no national competency standards have been established at national level. However, the learning outcomes in this course relate to ASF level Content X-ray Equipment Electron source, beam focusing, electron acceleration. Equipment design, roentgen output, duty cycle, focal spot size, heel effect, tube efficiency. Mono and bipolar tubes. Rod anode, rotating anode, fine and dual focus tubes. Glass and metal/ceramic tubes. X-ray circuits, self rectified, half wave rectified Greinacher, Graetz, Villard, constant potential. Tube windows - Beryllium and glass window. Control equipment. Effect of voltage and current. Intro to special equipment eg. Linear Accelerators, Betatron, Van de Graaf. Gamma Ray Sources Spectra, activities, decay factors, energies of principal lines, advantages, limitations, applications of Ir192, Co60, Yb169. Comparison on X-ray and gamma ray sources on basis of energy and intensity. Radio-isotope containers, types, construction, materials, ancillary equipment, operation, safety. Shielding Thickness

2 Shielding theory. Properties of shield materials. Camera types and design and accessories. Handling isotope cameras. Safe working distance for X-ray & Gamma ray exposures - calculation. Photographic Aspects Principles of image formation. Film types, emulsions, classes, properties. Film selection. Film density, characteristic curves, gradient, film gamma, film contrast, exposure latitude. Inherent unsharpness Intensifying screens - lead, fluorescent, fluorometallic Processing chemicals - developer, stop bath, fixer, wash Effect of time and temperature. Tropical processing. Need for washing. Requirements for archival storage. Dark room control and layout. Chemical processes for intensification and reduction of films. Effect on quality. Film artefacts - source, appearance, avoidance. Radiographic Sensitivity Radiographic contrast - effect of energy, material, scatter, film. Definition - Geometric, film and total unsharpness, geometric factors, film factors. Determination. Radiographic sensitivity - definition. Radiographic undercut - use of screens and masking. Assessing Sensitivity Image quality indicators - types, applications. Calculation of IQI sensitivity. Relevance to flaw sensitivity. Undercut comparator shims. Exposure calculations Set-up procedures. Effect of X-ray & gamma ray energy. Effect of tube current and source activity Determining exposure geometry. Control of geometric unsharpness. Relationship of source size, distance and object/film distance. Reciprocity Law. Choice of films, screens, cassettes. Preparation and use of exposure charts, radiographic equivalence charts. Use of distance squared law and characteristic curves. Exposure calculations taking into account all variables. Preparation of exposure charts and characteristic curves. Exposure Techniques Selecting the views - number of exposures, minimising use. General and local views, beam centring, Directional and panoramic exposures. Identification of radiographs - overlap, markers, job TAFE METAL AND ENGINEERING NATIONAL CURRICULUM PROJECT Page 2 of 9

3 (correlation) numbers, numbering of joints. Image distortion, object/focus/film distance, section equalisation. Choice of source/energy, film, screens. Use and placement of IQI's. Preparation and use of sensitivity charts. Viewing and Interpretation Viewing radiographs - Equipment types, determination of brightness with photographic exposure meter. Background lighting, operator factors. Preliminary assessment - artefacts, IQI sensitivity. Recording and reporting. Acceptance codes, standards. Radiography of Welds Welding processes (revision only). Defects in welds - appearance, cause, significance. X-ray and gamma ray techniques - Code requirements. Radiography of Castings Foundry processes (revision only). Defects in castings - appearance, cause, effect. X-ray and gamma ray techniques -Code requirements. Radiography of aircraft parts Aircraft structures (revision only). Defects in aircraft X-ray and gamma ray techniques, codes, ANO's, ANR's Radiography of other Materials Assemblies - electrical, mechanical. Effect of beam divergence Plastics, ceramics, graphite, foods, wood Autoradiography of radioactive materials Site Radiography Specific problems of radiography at a field site Equipment required Safety aspects Special Radiographic Techniques Depth location using double exposures. Two exposures at right angles, stereo radiography. Multi film techniques for section equalisation. Enlargement and projection. Density analysis for determining thickness of flaw. Applications of low voltage and high voltage Radiography Types of materials radiographed Industrial applications Set up procedures TAFE METAL AND ENGINEERING NATIONAL CURRICULUM PROJECT Page 3 of 9

4 6. Assessment strategy Assessment method Competency based assessment applies. Assessment should be carried out by gathering evidence using a variety of methods or instruments that have validity according to the learning being assessed. Multiple choice and short answer questions. Written assignments and demonstrated competence through assigned tasks. Final assessment will be by a written examination and practical examination as required by AS3998 for Level 2 Certification. Conditions of assessment 7. Learning outcome details 8. Learning outcome 1 Assessment will be conducted by suitably qualified assessors, as required by AS3998. The candidate will have access to any equipment, materials and documentation as required for the assessment. On completion of this module, the learner will be able to Describe the principal types of X-ray generator and the principal radioisotopes used in industrial radiography, including the important aspects of the radiation produced by each radiation source, and the effect these factors have on radiographic quality Assessment criteria 1.1 Describe the various X-ray tubes and generator circuits used in industrial X-ray equipment, and the effect they have of radiation output. Determine focal spot size and beam spread for an X-ray tube. 1.2 Describe the principal radioisotopes used in industrial radiography, their important properties, and the properties of the radiation emitted by these radioisotopes. Select a suitable source for particular applications. 1.3 Compare the outputs of X-ray and gamma ray sources on the basis of energy and intensity of radiation. Learning outcome Determine the shielding thicknesses and safe working distances for X-ray and gamma ray radiography. Describe the photographic aspects of radiographic film exposure and development. Assessment criteria 2.1 Describe the different types of radiographic film and their classifications. 2.2 Describe the factors that affect the exposure of radiographic film. TAFE METAL AND ENGINEERING NATIONAL CURRICULUM PROJECT Page 4 of 9

5 2.3 Describe the principal components of radiographic film development chemicals and their purpose. 2.4 Select most suitable film/screen combinations for particular circumstances. 2.5 Identify film artefacts and determine their source and cure. 2.6 Assess the effect of processing variables on film quality. Learning outcome 3 Describe the factors that affect radiographic quality and apply these principles in producing optimum quality radiographs. Assessment criteria 3.1 Identify the primary and secondary factors that affect radiographic sensitivity. 3.2 Identify the means available for assessing radiographic sensitivity, and calculate sensitivity values using these devices. Learning outcome 4 Describe the methods for setting up and producing a satisfactory radiograph using X-ray and gamma ray sources. Assessment criteria 4.1 Calculate radiographic exposures to achieve a specified radiographic film density and sensitivity for a variety of industrial applications taking into account the full range of factors that affect quality of a radiograph Students will set up for various geometries and produce radiographs to stated standards. 4.3 Describe the factors that affect radiographic sensitivity. 4.4 Determine required source/film geometry and number of exposures necessary for a variety of industrial radiographic applications. 4.5 Assess radiographic sensitivity using different types of IQI. Learning outcome 5 Describe and set up the conditions necessary to view and interpret radiographs. Assessment criteria 5.1 State the conditions necessary to view and interpret radiographs. 5.2 Design and/or set up a radiographic viewing facility. 5.3 View and report radiographs in accordance with published TAFE METAL AND ENGINEERING NATIONAL CURRICULUM PROJECT Page 5 of 9

6 codes and standards. Learning outcome 6 Discuss, describe and carry out radiography of welds, castings and assemblies and non-metallic materials using standard procedures to recognised standards, and interpret those radiographs in accordance with acceptance codes and standards. Assessment criteria 6.1 Satisfactorily set up and radiograph welds, castings, assemblies and non-metallic specimens in accordance with national standards. 6.2 Interpret and report radiographs of welds, castings, assemblies and non-metallic specimens in accordance with national acceptance codes and standards. 6.3 Demonstrate knowledge of requirements for site radiography by setting up work using the appropriate code and safety procedures to ensure the safety of themselves and the general public. Learning outcome 7 Discuss and describe specialised radiographic techniques, including very high voltage and low voltage radiography, and techniques for specialised applications. Assessment criteria 7.1 Describe the theory, procedures and applications for high voltage and low voltage radiography. 7.2 Describe the procedures for specialised radiographic applications such as telegraph poles, assemblies, defect depth determination and corrosion assessment in pipes. 7.3 Demonstrate methods for defect depth determinations, apply section equalisation techniques, use density analysis for determining flaw thickness and pit depth in accordance with relevant standards and codes. 7.4 Set up and produce radiographs for specialised applications. 7. Delivery of the module This module may be taught by active participation, illustration, demonstration and description. This module is practical in nature and theoretically integrated to complement the acquisition of practical skills. TAFE METAL AND ENGINEERING NATIONAL CURRICULUM PROJECT Page 6 of 9

7 Delivery strategy This module may be taught and assessed on or off-the-job. The module has a high practical content. Theory and practice will be taught concurrently. There will be a range of learning activities including modified lectures, practical work and project work. Resource requirements Major texts and references Human resources trainer/teacher/mentor Physical resources appropriately equipped training room relevant equipment and information legislative and regulatory documents RECOMMENDED TEXT Radiographic Testing - P.A. Sheedy - NSW TAFECOM. PRACTICAL TEXT Practical Radiography - P.A. Sheedy REFERENCES 1. Non-Destructive Testing Handbook, 2nd Edition, Vol. 3, Radiographic Testing. ASNT, Industrial Radiography, R. Halmshaw, Radiographic NDT, G.L. Becker. Du Pont NDT Systems, Industrial X-ray Interpretation, J.G. Schneeman. ASNT, Industrial Radiography, Agfa Corporation. 6. NDE Characteristics of Pipe Weld Defects, EPRI, Radiographs of Welds, IIW, Radiographic Testing Classroom Handbook, ASNT. STANDARDS AS 1929 AS 2177/1 Non-Destructive Testing - Glossary of Terms. Non-Destructive Testing -Radiography of welded TAFE METAL AND ENGINEERING NATIONAL CURRICULUM PROJECT Page 7 of 9

8 Butt Joints in Metal - Methods of Test. (under review as DR91258) As 2177/2 Non-Destructive Testing - Radiography of Welded Butt Joints in Metal - Image Quality Indicators and Recommendations for Their Use. (under review) AS 2452/1 Non-Destructive Testing - Determination of Wall Thickness of Pipe by use of Radiography. AS 2452/2 Non-Destructive Testing - Determination of Remaining Wall Thickness of Corroded Pipe by use of Radiography. AS 3507 Non-Destructive Testing - Radiography of Steel Castings and Classification of Quality. AS Z5/2 Imperfections. Welding Terms and Symbols - Fusion Weld ASTM E446 Reference Radiographs - Steel Castings up to 51 mm thick ASTM E186 Reference Radiographs - Steel Castings 51 to 114 mm thick ASTM E155 Castings Reference Radiographs - Aluminium/Magnesium ASTM E802 - reference radiographs - Gray Iron Castings up to 114 mm thick NOTE: Reference should also be made to various structural, pipe and pressure vessel codes and standards for defect limitations as revealed by radiographic testing. Occupational health and safety requirements Learners and/or employees undertaking this module should have demonstrated competencies as defined in the Metal & Engineering Industry Standards Unit No 1.2F - Apply principles of OH&S in the work environment. This would apply in the classroom, practical room or workplace. TAFE METAL AND ENGINEERING NATIONAL CURRICULUM PROJECT Page 8 of 9