Cracking in tack weld joint

Cause of cracking in tack weld joint?
How to avoid this cracking?

Caused by:-
lacked of fusion of parent metal/not enough filler metal deposited into the weld, parent metal to cold, the tack weld to small/ not long enough, wrong filler metal, welding machine settings wrong/not as per WPS etc.

Avoid by ensuring:-
Correct WPS settings is followed/WPS is implemented properly with regard to filler metal, preheat of weld area, weld sequence etc., ensure proper heat input during welding, qualified welder to execute job function.


Min. lenght of tack weld? and standards reference?

3 times the thickness of parent metal.
ASME B31.1

1 Like

AWS D1.1 Tack welds located outside the joint groove shall terminate not closer than
1/2 in [12 mm] from the edge of the connected part.

ASME IX table 469.1 note 2: Tack weld are not limited by pipe or tube diameters when their aggregate length does not exceed 25% of the weld circumference.