Definition: Abrupt changes in the profiles of weld bead ripples Main Causes: (1) Too low or high welding amperage or voltage (2) Inappropriate electrode manipulation (irregular, too fast, or too slow) (3) Too much moisture in coatings (SMAW) or fluxes (SAW) (4) Too much flux-burden height (SAW) Preventive Measures: (1) …
What is a common cause of an unevenly sized weld bead?
Uneven weld beads
This is caused by the high arc pressure on the weld pool. The result of this effect is that the penetration is excessive for the wire size in use, causing the molten metal to be ejected over the edge of the joint and sometimes also causing lack of fusion.
What factors affect a weld bead shape?
In order to make the four types of weld beads with different shapes by factors such as length, angle, and area, the welding process, wire feeding speed, and joint shape were changed.
How should the ripples on the weld bead appear?
Bead ripples appear along the length of the weld bead as undulations with measurable differences in height by as much as 1/8” (3 mm). Often the height of the bead ripple on a welded pipe is a function of the heat that has gone into the weld process: the higher the heat, the greater the height of the bead ripple.
How do you prevent the occurrence of uneven weld bead ripples during on your actual welding?
Irregular welds include too wide or too narrow, those with an excessively convex or concave surface, and those with coarse, irregular ripples.
To avoid excess reinforcement
- Keep the torch moving at a proper speed. …
- Set your amperage correctly and avoid excess heat.
- Adjust your voltage so that it is not too low.
What causes overlap in welding?
Overlap occurs when molten metal flows over the surface of the base material and then cools without fusing with the base material. A typical cause of overlap is the supply of too much weld metal due to low welding speed. Overlap in fillet welds is caused by the droop of excessive molten metal due to gravity.
What causes porous welds?
Porosity is caused by the absorption of nitrogen, oxygen and hydrogen in the molten weld pool which is then released on solidification to become trapped in the weld metal. … Leaks in the gas line, too high a gas flow rate, draughts and excessive turbulence in the weld pool are frequent causes of porosity.
What adjustments change weld bead reinforcement?
Increase in water depth or pressure decreases bead width, but increases penetration, and reinforcement. Increase in voltage will increase bead width, penetration, and reinforcement.
What is form factor in welding?
vi) Form factor is the ratio of the weld pool width to its maximum depth. Width is the root opening plus the total penetration into the base metal.
What are the different types of beads in welding?
Welding Beads – Types Of Beads
- TIG Welding Beads.
- Stick Welding Beads.
- MIG beads.
- Flux Cored MIG Beads. Conclusion.
What is imperfection in welding?
A welding defect is any flaw that compromises the usefulness of a weldment. … Welding imperfections are classified according to ISO 6520 while their acceptable limits are specified in ISO 5817 and ISO 10042.
What is the most common type of incomplete fusion during a weld?
Incomplete fusion occurs when individual weld beads don’t fuse together, or when the weld beads don’t fuse properly to the base metal you’re welding, such as in below. The most common type of incomplete fusion is called overlap and usually occurs at the toe(on the very top or very bottom of the side) of a weld.
What is incorrect weld size?
6. Incorrect Weld Size – This can be either a weld that is too big or too small. Although big welds are preferred over small welds it is still detrimental at times to have a big weld due to excessive heat input, weld stresses and distortion.
What are the different welding positions?
4 Basic Welding Positions
- Flat Position (1G and 1F)
- Horizontal Position (2G and 2F)
- Vertical Position (3F and 3G)
- Overhead Position.
What are the different types of welding defects?
Following are the types of welding defects:
- Porosity and Blowholes.
- Weld crack.
- Incomplete fusion.
- Slag inclusion.
- Incomplete penetration.