In this course, we will cover the basics (such as tensile, impact, hardness) as well as more advanced subjects (such in-situ replica, chemical analysis).
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 behavior under different loads. These tests are generally much easier to get information about any material, and are easier to interpret than non-destructive testing.
Destructive testing is most suitable and economic for objects which will be mass produced, asthe 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.
Whom can attend?
Any B-Tech, Graduate/Diploma/ITI Holders may Join for this Course.
Course Content include common methods used in Destructive Examination
1. Tensile testing
2. Impact testing
3. Hardness testing
4. Spark testing
1. 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.
2. 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.
3. 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
4. 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
- Wrought iron
- Mild steel
- © Steel with 0.5 to 0.85% carbon
- High-carbon tool steel
- High-speed steel
- Manganese steel
- Mushet steel
- Special magnet steel