Which discontinuities are caused during welding?
Weld discontinuities can be defined as “an interruption of the typical structure of a weld, such as a lack of homogeneity in the mechanical, metallurgical or physical characteristics of the weld.” Weld discontinuities include porosity, slag inclusions, incomplete fusion, incomplete joint penetration, excessive melt- …
What are the causes of welding defects?
Causes:
- Too high weld current.
- Too fast weld speed.
- The use of an incorrect angle, which will direct more heat to free edges.
- The electrode is too large.
- Incorrect usage of gas shielding.
- Incorrect filler metal.
- Poor weld technique.
What types of discontinuities are caused by high welding current?
What Are Some Common Welding Discontinuities?
- Porosity. Porosity occurs when gas becomes trapped in the weld pool, forming permanent bubbles as the metal cools from a liquid state back to a solid.
- Inclusions.
- Inadequate Joint Penetration.
- Incomplete Fusion.
- Arc Strikes.
- Overlap.
What are 5 welding defects?
Following are the types of welding defects:
- Porosity and Blowholes.
- Undercut.
- Weld crack.
- Incomplete fusion.
- Slag inclusion.
- Incomplete penetration.
- Spatter.
- Distortion.
How can you prevent welding discontinuities?
You’ll need to remove the impurities in your metal and preheat it as required. Additionally, use the proper joint design for the material and properly cool the welded area. Be sure to weld enough sectional areas, too. Use the right amperage current and welding speed.
How can welding discontinuities be prevented?
Here are the various ways to prevent welding defects;
- Use of Low Hydrogen Filler Metals. There are many manufactures out there who offer a wide variety of products.
- Proper Matching of Filler Metal and Base Material Strength.
- Pre- and Post-Weld Materials Correctly.
- Implementation of Proper Filler Storage.
- Proper Training.
What are the different types of welding defects?
We can break down weld defects into the following main categories:
- Inclusions.
- Lack of fusion.
- Porosity.
- Undercut.
- Under-fill.
- Cracks.
- Excess reinforcement and excess penetration.
- Over-roll/Overlap.
What are the two types of welding defects?
Welding defects are broadly classified into two categories, and those are: External welding defects (Defects occur on the upper surface of the welded work). Internal welding defects (Defects occur under the surface of the welded work).
What is welding defect and its types?
Internal Welding Defects are defects that occur at some depth in the material. They are visually invisible since they are not present on the surface, but they carry equal weight as the external ones. These defects include incomplete fusion, slag inclusion, and incomplete penetration.
What is the difference between a weld defect and discontinuity?
A Discontinuity is an objective lack of material, an interruption in the physical consistence of a part while a Defect is an excessive conditions, outside the acceptance limits, which risks to compromise the stability or the functionality of the welded structure. It is very hard to perfect welding.
What is the most common welding defects?
What are common weld defects?
- Lack Of Penetration or Incomplete Penetration.
- Lack Of Fusion or Incomplete Fusion.
- Undercut.
- Spatter.
- Slag Inclusions.
- Cracks.
- Porosity.
- Overlap.
How do you identify weld defects?
What are common weld defects?
- Lack Of Penetration or Incomplete Penetration.
- Lack Of Fusion or Incomplete Fusion.
- Undercut.
- Spatter.
- Slag Inclusions.
- Cracks.
- Porosity.
- Overlap.
What are the ways to distinguish discontinuities in a weld profile?
These discontinuities are generally detected through visual inspection of the weld, however, some are detectable through other inspection methods such as radiography, liquid penetrant, and magnetic particle inspection.