Weld Defects Causes and Remedies Quiz and Flashcards

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Questions and Answers

Match the following welding problems with their possible causes:

Distortion = Excessive heat input Incomplete Fusion = Insufficient heat input Undercut = Improper welding technique Porosity = Work piece dirty

Match the following welding problems with their corrective actions:

Distortion = Use restraint clamp to hold base metal in position Incomplete Fusion = Increase amperage and select larger electrode Undercut = Adjust work angle or widen groove to access bottom during welding Porosity = Remove all grease, oil, rust, paint, coating, slag & dirt from work surface before welding

Match the following welding techniques with their benefits:

Increasing travel speed = Reduces distortion Making tack welds along joint before starting = Reduces the risk of incomplete fusion Selecting smaller electrode = Maintains steady travel speed Holding arc on groove side walls = Improves access to bottom of weld during welding

Match the following welding terms with their definitions:

Distortion = Contraction of weld metal during welding that forces base metal to move Incomplete Fusion = Failure of weld metal to fuse completely with base metal or a proceeding weld bead Undercut = A groove melted into the base metal adjacent to the weld toe or weld face and left unfilled by weld metal Porosity = Presence of gas pockets or voids in weld metal Signup and view all the answers

Match the following welding materials with their effects on weld quality:

Grease = Leads to poor weld quality Oil = Leads to poor weld quality Rust = Leads to poor weld quality Paint = Leads to poor weld quality Signup and view all the answers

Match the following welding techniques with their potential drawbacks:

Selecting larger electrode = Can lead to excessive heat input and distortion Using restraint clamp = Can result in deformation of base metal Making tack welds along joint = Can lead to incomplete fusion if not done correctly Predicting anticipated weld distortion = Can be difficult to accurately predict and plan for Signup and view all the answers

Match the weld defects with their possible causes:

Porosity = Arc length too long Excessive Spatter = Work piece dirty Lack of Penetration = Amperage too high for electrode Burn-through = Improper joint penetration Signup and view all the answers

Match the weld defects with their corrective actions:

Porosity = Remove all grease, oil, rust, paint, coating, slag & dirt from work surface before welding Excessive Spatter = Reduce travel speed Lack of Penetration = Increase amperage & Select larger electrode Burn-through = Select lower amperage Signup and view all the answers

Match the weld defects with their descriptions:

Porosity = Shallow fusion between weld metal and base metal Excessive Spatter = Scattering of molten metal particles that cool to solid form near weld bead Lack of Penetration = Small cavities or holes resulting from gas pocket in weld metal Burn-through = Weld metal melting completely through base metal resulting in holes Signup and view all the answers

Match the corrective actions with the weld defects they address:

Reduce arc length = Porosity Decrease amperage or select larger electrode = Excessive Spatter Keep arc on leading of weld puddle = Lack of Penetration Select lower amperage = Burn-through Signup and view all the answers

Match the causes of weld defects with their corresponding defects:

Arc length too long = Porosity Improper joint penetration = Lack of Penetration Amperage too high for electrode = Excessive Spatter Excessive heat input = Burn-through Signup and view all the answers

Match the weld defects with their characteristics:

Porosity = Holes or cavities in the weld metal Excessive Spatter = Molten metal particles scattered near the weld bead Lack of Penetration = Shallow fusion between weld metal and base metal Burn-through = Holes in the base metal where no metal remains Signup and view all the answers

Study Notes

Welding Defects

Welding defects are defined as weld surface irregularities, discontinuities, imperfections, or inconsistencies that occur in welded parts.
Defects can result in rejection of parts and assemblies, costly repairs, reduction of performance, and catastrophic failures.

Distortion

Distortion is the contraction of weld metal during welding that forces base metal to move.
Possible causes: excessive heat input.
Corrective actions:
- Use restraint clamp to hold base metal in position.
- Make tack weld along joint before starting weld operations.
- Predict anticipated weld distortion and pre-camber base metal.
- Select lower amperage for electrode.
- Increase travel speed.
- Weld in small segments and allow cooling between welds.

Incomplete Fusion

Incomplete fusion is the failure of weld metal to fuse completely with base metal or a preceding weld bead.
Possible causes: insufficient heat input, improper welding technique, and work piece dirty.
Corrective actions:
- Increase amperage and select larger electrode.
- Place stringer bead in proper locations at joint during welding.
- Adjust work angle or widen groove to access bottom during welding.
- Momentarily hold arc on groove side walls when using weaving technique.
- Keep arc on leading edge of weld puddle.
- Remove all grease, oil, rust, paint, coating, slag, and dirt from work surface before welding.

Porosity

Porosity is small cavities or holes resulting from gas pockets in weld metal.
Possible causes: arc length too long, work piece dirty, and damp electrode.
Corrective actions:
- Reduce arc length.
- Remove all grease, oil, rust, paint, coating, slag, and dirt from work surface before welding.
- Use dry electrode.

Excessive Spatter

Excessive spatter is the scattering of molten metal particles that cool to solid form near weld bead.
Possible causes: amperage too high for electrode, arc length too long, and voltage too high.
Corrective actions:
- Decrease amperage or select larger electrode.
- Reduce arc length or voltage.

Lack of Penetration

Lack of penetration is shallow fusion between weld metal and base metal.
Possible causes: improper joint penetration, material too thick, and improper weld technique.
Corrective actions:
- Improve joint penetration and design to provide access to bottom of groove.
- Keep arc on leading edge of weld puddle.
- Reduce travel speed.
- Increase amperage and select larger electrode.

Burn-Through

Burn-through is weld metal melting completely through base metal, resulting in holes where no metal remains.
Possible causes: excessive heat input.
Corrective actions: select lower amperage.

Mark/Locate Weld Defects

Identify/determine location of weld defects in accordance with industry standard.
Mark weld defects for repair in accordance with industry standard.
Perform procedures in locating weld defects as per approved procedures.

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Description

Test your knowledge on weld defects, their causes, and remedies. Learn about weld surface irregularities, discontinuities, imperfections, and inconsistencies that could lead to part rejection or catastrophic failures.