282 Gas Tungsten Arc Welding Handbook Copyright Goodheart-Willcox Co., Inc. 282 Gas Tungsten Arc Welding Handbook Summary • Inspections are made during and after the manufacturing cycle to ensure that parts meet specifi cations. Types of inspection include nondestructive examination (NDE), in which no portion of the completed weld is destroyed, and destructive tests, in which the weld is destroyed. Weld integrity inspections may also be required in addition to the nondestructive test requirements to verify the weld quality. • NDE includes visual tests, penetrant tests, magnetic particle tests, ultrasonic tests, and radiographic tests. Destructive tests include bend tests, tensile tests, notch-toughness tests, cross section tests, and nick-break tests. Weld integrity inspections include pressure tests, hardness tests, corrosion tests, and ferrite tests. • Intended weld repairs must be evaluated as to whether the discontinuity should be removed. Repairing a completed weld could cause buckling, distortion, or misalignment of the reworked area. In some cases, a discontinuity can be left in a weld without affecting the weld’s function. • Repairs can be made to correct dimensional problems, surface defects, and internal defects. Common surface defects include longitudinal, transverse, or crater cracks undercut at the edges of the weld porosity cold laps and incomplete penetration. Internal defects are generally found by radiographic and ultrasonic testing. • Stringer beads should be used for welding repairs in order to minimize shrinkage of the joint. If the weld repair is deep, an X-ray should be made after two or three completed passes to confi rm that the original crack has been fully repaired and new cracks have not formed. Where the grain size must be controlled throughout the repair, temper beads should be used to reduce the surface grain size. • All nondestructive testing required for fi nal acceptance of the weld must be completed after the weld repair is done. Repairs can cause new problems in a weld. Review Questions Answer the following questions using the information provided in this chapter. 1. Inspections and tests made on a weld that do not destroy any portion of the completed weld are called _____. 2. A(n) _____ test is used to identify bad welds before other more expensive and time- consuming types of inspection are performed. 3. What is the difference between a fl aw and a defect? 4. A penetrant test (PT) will only reveal disconti- nuities that are located _____. 5. In a magnetic particle test, _____ particles form a pattern on the surface of the material where a defect is located. 6. What does an ultrasonic test of a weld reveal? 7. List four factors that can cause misinterpretation of an ultrasonic test. 8. Radiographic tests use the ability of short wave- length radiations, such as _____ or _____, to penetrate opaque material. 9. What is the purpose of a penetrameter? 10. List the three types of bend tests. 11. List the three mechanical values of a weld deter- mined by tensile tests. 12. _____ tests are used to defi ne the ability of welds to resist cracking or crack propagation at low temperatures under loads. 13. A pressure test that uses liquid is called a(n) _____ test. 14. In a corrosion test, test weldments are sprayed with a(n) _____ mixture and allowed to corrode. 15. Why should all rejected welds be thoroughly reviewed before attempting a repair? 16. List three conditions that require dimensional repair. 17. What should be avoided when grinding out undercut defects? 18. What type of defects located in the body of a weld are very hard to locate using grinding or routing? 19. What should be done when making a deep weld repair to confi rm that new cracks have not formed? 20. _____ beads reduce the surface grain size and are removed after welding.