How do gamma rays compare with X-rays when applied to RT of welds?Īnswer: Gamma rays have greater penetration ability, but give poorer contrast.Ģ6. When the radiation source is located inside piping with the film located outside, single-wall exposure and single-wall view, name this type of exposure?Ģ5. Name 5 common film artifacts that may be cause for rejection of Radiographic Film?Īnswer: Film Scratches, light leaks, chemical stains, fogged film, static marks, water marks, streaks, crimp marks, finger marks, lint, dirt.Ģ4. A localized darker density Radiographic image with fuzzy edges in the center of the width of the weld image that may or may not be wider than the width of the root pass image is most likely what?Ģ3. What is the indication most likely to be?Ģ2. A dark narrow area 2-3mm wide appears on a radiograph all along the edge of the area representing the weld. If a product is to be stress relieved, why is it important to use exactly the same RT procedure before and after stress relieving?Īnswer: So that a baseline evaluation is performed to ensure that borderline indications are not misinterpreted after stress relief.Ģ1. List 3 disadvantages of RT over other NDT Methods.Īnswer: Radiation Safety Precautions, Planar defects not readily detectable, Heavy equipment.Ģ0. Name an NDT method and technique that employs a reflected sound beam that can be used for the volumetric examination of welds?Īnswer: Ultrasonic Testing using Shear Wave Technique provides good volumetric exam coverage.ġ9. Indications with Liquid Penetrant Testing are easily seen if the surface has been prepared by grinding prior to testing? True/false? Why?Īnswer: False, because grinding can smear metal and mask/cover discontinuities.ġ8. How is Magnetic Particle inspection of a weld using the wet continuous test method performed?Īnswer: The particles (usually fluorescent) are sprayed, poured on or applied by immersion and the magnetizing current is applied while the particles are still flowing.ġ7. Name 3 of the 5 mechanical tests in ASME IX employed for procedure & performance qualifications?Īnswer: Tension, Guided Bend, Fillet-weld, Notch-toughness & Stud-weld tests Mechanical/NDT (assume SMAW process used for all questions)ġ6. Using GTAW process, describe what happens to a weld without proper purging/back gassing on SS material?ġ5. Where would cracking most likely occur from excessive current input in a single pass weld?ġ4. What dimension is measured to determine the size of a convex fillet weld?ġ3. What dimension is measured to determine the size of a concave fillet weld?ġ2. What are several likely causes of porosity in carbon steel welds using the SMAW process?Īnswer: Poor welding technique and equipment, excessive wind, moisture & weld contaminants.ġ0. Answer: Moisture in the metal and electrode coating, oil, elemental Hydrogen in the base metalĩ.
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