1. Teknologi Dan Rekayasa
TESTING WELDS

2. WELD TESTING METHODS Objectives :
After studying this unit the student will be able to identify weld testing methods
Teknologi dan Rekayasa

3. WELD TESTING METHODS
Workpieces may be subjected to heavy loads. For this reason it is necessary to ensure that the workpieces is capable of meeting the demands placed upon it.
Two different methods are used for testing welds. They are classified as either :
Destructive
Non destructive
Teknologi dan Rekayasa

4. WELD TESTING METHODS The destructive weld test
Destructive weld test include :
With a tensile testing machine
Bending test, wedge test
Notch impact test
Hardness test
Teknologi dan Rekayasa

5. WELD TESTING METHODS The non destructive weld test
Non destructive weld test include :
Surface defects
Magnetic Particle Inspection
Dye Penetrant Inspection
Eddy Current Testing
Radiographic Inspection
Ultrasonic Testing
Teknologi dan Rekayasa

6. The destructive weld test
Tensile testing machine
A test piece is turned from a weldment or cut from across a weldment to specified dimensions.
The specimen is placed in a tensile machine.
Readings taken from the machine show tensile strength, elastic limit, yield point, elongation and reduction of area.
Teknologi dan Rekayasa

7. The destructive weld test
2. Bending test, wedge test
Bend test are the reliable and convenient methods for determining the soundness or uniformity and ductility of a weld
Teknologi dan Rekayasa

8. The destructive weld test
3. Notch impact test
Impact testing is used to measure relative shock and impact resistance of a test specimen.
Two types of equipment are in common use Izod and Charpy Impact testing machine.
Teknologi dan Rekayasa

9. The destructive weld test
4. Hardness test
Hardness tests are effective in determining the relative hardness of the weld area as compared with the base metal.
The standard hardness machines are known as Brinell and Rockwell.
Teknologi dan Rekayasa

10. The non destructive weld test
Surface defects
Defect such as arc burn, large cracks, undercuts, and in many cases lack of penetration can be evaluated by visual examination and the condition of the weldment assessed in terms of the appropriate specifications.
Teknologi dan Rekayasa

11. The non destructive weld test
2. Magnetic Particle Inspection
The magnetic particle method of inspection uses a strong magnetizing current and a finely divided powder suspended in a liquid to detect lack of fusion, very fine crack, and inclusions or internal flaws which are slightly below the surface in weldment.
Teknologi dan Rekayasa

12. The non destructive weld test
3. Dye Penetrant Inspection
In dye penetrant inspection surface defect are found by the use of proprietary dyes suspended in liquids which have high fluidity.
In this test the surface of the weldment, which must be clean and dry, is coated with a thin film of the penetrant.
Teknologi dan Rekayasa

13. The non destructive weld test
4. Eddy Current Testing
Eddy current testing used electromagnetic energy to detect discontinuities in weld deposits and is effective in testing both ferrous and nonferrous materials for porosity, slag inclusions, internal cracks, external cracks, and lack of fusion.
Teknologi dan Rekayasa

14. The non destructive weld test
5. Radiographic Inspection
Radiographic Inspection is a method of determining the soundness of a weldment by means of rays which are capable of penetrating through the entire weldment.
Teknologi dan Rekayasa

15. Radiation tests by X-ray or gamma rays
The non destructive weld test
Radiation tests by X-ray or gamma rays
X-ray tube
Test piece
Film plate
Test procedure :
If a film is positioned on one side of a weld to be tested and the weld is irradiated from the other side, the presence of defects are seen on the film.

16. The non destructive weld test
6. Ultrasonic Testing
In ultrasonic testing high frequency vibrations or waves are used to locate and measure defect in both ferrous and non ferrous materials.
This method is very sensitive, and is capable of locating very fine surface and subsurface cracks, as well as other internal defect.
Teknologi dan Rekayasa

17. The non destructive weld test
Test procedure :
Ultrasonic waves are emitted by ultrasonic equipment via a sonic head.
The sonic head is attached to the workpiece, which is penetrated by the ultrasonic waves.
The sound waves are reflected by the back wall of the workpiece and by any existing weld defects (echo).

18. The non destructive weld test
Ultrasonic waves have a very high frequency and short wave length.
Audible sound :
– Hz
Ultrasonic sound :
– Hz

19. THE END
Teknologi dan Rekayasa