Identifying common welding defects
Preventing and fixing problems with your welds
put the pieces to be welded in place to make sure they fit together and line up properly.
Most Common Types of Welding Defects
Here’s a list of the most common causes of incomplete penetration welding defect.
The groove you’re welding is too narrow, and the filler metal doesn’t
reach the bottom of the joint.
don’t melt together on the first pass.
✓ You’re welding a joint with a V-shaped groove and the angle of the
groove is too small (less than 60 to 70 degrees), such that you can’t
manipulate your electrode at the bottom of the joint to complete
✓ Your electrode is too large for the metals you’re welding.
✓ Your speed of travel(how quickly you move the bead) is too fast, so
not enough metal is deposited in the joint.
✓ Your welding amperage is too low.If you don’t have enough electricity
going to the electrode, the current won’t be strong enough to melt the
Here are a few more usual suspects when it comes to incomplete fusion
✓ You’re using the wrong electrode for the material that you’re welding.
✓ Your speed of travel is too fast.
✓ Your arc length is too short.
✓ Your welding amperage is set too low.
If you think your incomplete fusion may be because of a low welding amperage, crank up the machine! But be careful: You really need only
enough amperage to melt the base metal and ensure a good weld.
Anything more is unnecessary and can be dangerous.
✓ Contaminants or impurities on the surface of the parent metal(the metal
you’re welding) prevent the molten metal (from the filler rod or elsewhere
on the parent metal) from fusing.
✓ Your electrode is too large for the base metal you’re welding.
✓ Your arc is too long.
✓ You have your amperage set too high.
✓ You’re moving your electrode around too much while you’re welding.
Weaving your electrode back and forth is okay and even beneficial, but if
you do it too much, you’re buying a one-way ticket to Undercutting City
(which is of course the county seat for Lousy Weld County).
Common causes of slag inclusions include
✓ Failure to clean a welding pass before applying the next pass
Be sure to clean your welds before you go back in and apply a second weld bead.
✓ Slag running ahead of your weld puddle when you’re welding a V-shaped
groove that’s too tight
✓ Incorrect welding angle
✓ Welding amperage that’s too low
✓ Clean your weld joints properly after each pass.This task is especially
important when you’re brazing.
✓ Don’t go overboard with your use of flux.
✓ Make sure you’re using enough heat to melt the filler or flux material.
✓ Make sure all your materials are clean before you begin welding.
✓ Work on proper manipulation of your electrode.
✓ Try using low-hydrogen electrodes.
✓ Hot cracks:
quickly or cools down too quickly. If you’re having problems with hot cracking, try preheating your material. You can also postheat your material, which means that you apply a little heat here and there after you’ve finished welding in an effort to let the metal cool down more
✓ Cold cracks:
weld.) It generally happens only in steel, and it’s caused by deformities in the structure of the steel. You can guard against cold cracking by
increasing the thickness of your first welding pass when starting a new weld. Making sure you’re manipulating your electrode properly, as well as pre- and postheating your metal, can also help thwart cold cracking.
✓ Crater cracks:
electrode. The really annoying part about crater cracks is that they can cause other cracks, and the cracking can just kind of snowball from
there. You can control the problem by making sure you’re using the appropriate amount of amperage and heat for each project, slowing your
speed of travel, and pre- and postheating.
Say you’re welding a Tjoint. The vertical part of the Tsometimes pulls itself toward the weld joint. To account for that movement, simply tilt the vertical part out a little before you weld, so that when it tries to pull toward the weld joint, it pulls itself into a nice 90-degree angle!
The more heat you use, the more likely you are to end up with warpage, so be sure to use only the amount of heat you need. Don’t overdo it. Opting for a slower speed of travel while welding can also help to cut down on warpage.
You can keep spatter to a minimum by spraying with an anti-spatter compound (available at your welding supply store) or by scraping the spatter off the parent metal surface.
- Gas Metal Arc Welding (GMAW) or MIG Welding
- Flux shielded metal arc welding process principle
- Tungsten Inert Gas welding or TIG welding
- Advantages and Disadvantages of Submerged arc welding
- Submerged Arc Welding Working Principles and Uses
- Resistance Seam Welding (RSEW)
- Resistance Spot Welding
- TIG Aluminum Welding