2. Destructive Examination & Testing

3. 2 Destructive Examination Destructive Examination renders the weld or material unfit for further service.

4. 3 Common methods used in Destructive Examination Bend testing Tensile testing Impact testing Hardness testing Chemical analysis & Metallography Hydrostatic testing to destruction

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12. 11 Mechanical Testing Tension

13. 12 Tensile Strength Testing “Tensile” is a test in which a prepared sample is pulled until the sample breaks. Test Measurements are recorded in PSI (Pounds per Square Inch) E7018 = 70,000 PSI Tensile Test samples called “Tensile Bolts” can reveal a welds Tensile strength, Elastic limit, Yield point, and Ductility.

14. 13 Tensile Strength Testing The Elastic Limit of metal is the stress (load) it can withstand and still return to the original length after the load is released. Yield Strength occurs when the test sample stretches however will not return to its original length. Ductility is the ability of a metal to stretch or elongate before it breaks.

15. 14 Tensile Testing Strength Graph

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25. 24 Bending

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33. 32 Bend Testing Bend test samples are referred to as “Test Coupons” The most common bend tests are –Guided face and root bend testing –Guided side bend testing –Longitudinal root and side bend testing –Fillet weld bend testing –Unguided bend testing

34. 33 Bend Testing Sample Removal

35. 34 Bend Testing Sample Preparation

36. 35 Face Bend Testing

37. 36 Root Bend Testing

38. 37 Side Bend Testing

39. 38 Longitudinal Face Bend Testing

40. 39 Longitudinal Root Bend Testing

41. 40 Pipe Fillet Bend Testing

42. 41 Impact Testing

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44. 43 TEST MACHINE

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46. 45 CHARPY

47. 46 IZOD

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56. 55 An Impact tester uses a heavy pendulum that is able to measure the amount of force required to shear or fracture a test sample taken from welds “Heat Affected Zone” (HAZ) Impact testing may be performed using either the Izod or Charpy method. (Both methods are similar)

57. 56 A Charpy or Izod test measures the welds ability to withstand an Impact force. Low Charpy test readings indicate brittle weld metal Higher Charpy readings indicate the samples toughness.

58. 57 Hardness Testing

59. 58 1- scratch 2- dynamic 3- indentation

60. 59 Brinell

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64. 63 Vickers

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66. 65 Rockwell

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71. 70 VICKERS HARDNES

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74. Microhardness Testing Knoop and Vickers

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78. 77 Summary of Hardness testing Hardness may be defined as the resistance to permanent indentation. Three common hardness measuring tests are –Rockwell test –Scleroscope test –Brinell –Microhardness test

79. 78 Summary of Hardness testing The Rockwell testing machine operates somewhat like a press, using a indenter to penetrate the surface of the test sample. The depth of the indentation determines the materials hardness on a scale of 0- 100

80. 79 Summary of Hardness testing The Sceleroscpoe testing machine measures the amount “bounce” that a diamond tip hammer rebounds off the test sample after being dropped. The Brinell method presses the “indenter” into a sample for a given period of time. The ability for the sample to resist indentation determines hardness.

81. 80 Summary of Hardness testing Microhardness testers allow you to measure a materials hardness while leaving the least amount of damage possible on the metals surface. After the indenter is used a powerful microscope is used to determine the the amount of indentation into the components surface.

82. 81 Chemical Analysis Chemical analysis is used in metallurgical laboratories to determine the metals grain and crystalline structures. Samples are then place under a high power microscope to view the results. This is referred to as “Metalography”

83. 82 Hydrostatic Testing to Destruction Pressure testing or leak testing can be performed with either gasses or liquids. When this pressure exceeds the limitations of the structures design it will rupture under force. This rupture will allow engineers to understand the welds weakest areas.

84. 83 Used to determine the actual structure of the weld and parent metal Up to 50,000 times magnification with an electron beam microscope Polishing must be of a very high standard MICROSCOPIC

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87. 86 Examined using a magnifying glass. magnification from 2 to 20 time. it will show up slag entrapment or cracks polishing not as high as micro. MACROSCOPIC

88. 87 ETCHING REAGENTS These are acids used to show up different structures in metals For steels the most common is “1-2 % nitric acid in distilled water or alcohol. Aluminum uses a solution of 10-20% NaOH in water

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