Page 315 - CITS - Welder - Trade Practical

WELDER - CITS

EXERCISE 86 : Conduct Impact Testing

Objectives

At the end of this exercise, you will be able to:
• explain the necessity for destructive tests
• explain the different methods of destructive test of weldments
• explain the advantages and limitations of workshop and laboratory tests
• identify the specimen for destructive tests.

Job Sequence

• There are two main forms of impact test, the IZAD test and the chary test. Both involve striking a standard
specimen with a controlled weight pendulum travelling at a set speed. The amount of energy absorbed in
fracturing the test piece is measured and this gives an indication of the notch toughness of the test material.

• The impact testing method is pivotal for determining a materials ductile to brittle transition temperature and it
is ability to resist deformation due to impact loads. The charpy and IZAD test quantify the energy observed by
a material upon impact, while drop-weight and dynamic tear test provide additional data on material resistance
to impacts of varying intensities.

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