Basuc Weld Faults And Their Causes Flashcards Preview

Shield Metal Arc Welding 1 > Basuc Weld Faults And Their Causes > Flashcards

Flashcards in Basuc Weld Faults And Their Causes Deck (4)
Loading flashcards...

All weld defects

Incomplete penetration
Incomplete fusion
Slag inclusion


Types of cracking

Hot cracks, cold cracks

External cracks- crater, longitudinal and transverse

Internal cracks- underbead cracking


Types of distortion

Longitudinal- shrinks along the length and bows inwards

Transverse- tendency for the plates in a butt joint to pull together down the length of the joint.

Methods to prevent: tacks along the length or put a wedge 12in to 18in ahead of the welding to hold the plates apart or prespacing.

Angular- the face shrinks and pulls the two pieces together
Method to fix: on a tee joint weld the other side of the joint.


Distortion controls

•Avoid over welding
•Deposit the greatest amount of weld in the shortest amount of time (high rate of travel and use largest electrode possible)
•back-step welding sequence
•internment welding sequence
•Pre-bending or pre-spacing
•preheating and post-heating