Presented by:
Sujeet kumar kalelkar

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Destructive Examination & Testing
Destructive Examination
 Destructive testing, as the name suggests, involves the physical destruction of the completed metal in order to evaluate its characteristics.
 Destructive testing perform in order to understand a specimen's structural performance or material behaviour under different loads. These tests are generally much easier to get information about any material, and are easier to interpret than nondestructive testing.
 Destructive testing is most suitable and economic for objects which will be mass produced, as the cost of destroying a small number of specimens is negligible.
 It is usually not economical to do destructive testing where only one or very few items are to be produced.
for example - In the case of a building.
Common methods used in Destructive Examination
 Tensile testing
 Impact testing
 Hardness testing
 Spark testing
Tensile Strength Testing
 “Tensile Testing” is a test in which a prepared sample is pulled until the sample breaks.
 Test Measurements are recorded in PSI (Pounds per Square Inch) .
 Test samples called “Tensile Bolts” can reveal a welds Tensile strength, Elastic limit, Yield point, and Ductility.
 The Elastic Limit of metal means that stress is proportional to strain. 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.
Impact Testing
 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)
 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.
Hardness testing
 Hardness may be defined as the resistance to permanent indentation.
 Four common hardness measuring tests are
 Rockwell test
 Scleroscope test
 Brinell test
 Microhardness test
 Microhardness testers allow to measure a materials hardness while leaving the least amount of damage possible on the metals surface.
 the indenter is used a powerful microscope to determine the amount of indentation into the components surface.
 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
 The Scleroscope testing machine measures the amount of “bounce” that a diamond tip hammer rebounds the test sample after being dropped.
 In the Brinell method presses the “indenter” into a sample for a given period of time.
 The ability of the sample to resist indentation determines hardness.
 .
Technical Specificatio
Test loads - 500 to 3000 kg
 Capacity - Throat 200 mm
 Max test height - 410 mm
Spark Testing
 The shape and characteristic of sparks created when metal is ground will help to determine its properties.
 IE: carbon steel , mild steel.
Diagram of sparks for spark testing various types of ferrous materials
 (A) Wrought iron
 (B) Mild steel
 © Steel with 0.5 to 0.85% carbon
 (D) High-carbon tool steel
 (E) High-speed steel
 (F) Manganese steel
 (G) Mushet steel
 (H) Special magnet steel