AWS CWI Part A – WIT Chapter 9 Questions: Weld and Base Metal Discontinuities – Latest 19 MCQs

 

AWS CWI Part A – WIT Chapter 9 Questions and Answers

The AWS CWI Part A WIT Chapter 9 Questions and Answers practice test helps candidates recognize, describe, and evaluate common weld and base metal discontinuities encountered during welding inspection.

This free practice test contains 19 multiple-choice questions with four answer options, correct answers, and clear explanations.

The questions cover cracks, porosity, slag inclusions, incomplete fusion, incomplete joint penetration, undercut, underfill, overlap, weld profile conditions, arc strikes, laminations, seams, and lamellar tearing.

The AWS Welding Inspection Technology Fifth Edition officially identifies Chapter 9 as “Weld and Base Metal Discontinuities.” AWS states that the ten WIT chapters provide sources of knowledge for CWI examination preparation.

AWS currently describes CWI Part A – Fundamentals as a 150-question examination covering welding fundamentals, metallurgy, NDT, destructive testing, welding symbols, safety, WPS/PQR, fabrication mathematics, and related fundamental knowledge.

AWS CWI Part A WIT Chapter 9 Practice Test

This chapter-wise practice test focuses on:

Welding Inspection Technology Chapter 9 – Weld and Base Metal Discontinuities

Understanding discontinuities is one of the most important skills of a welding inspector.

An inspector must be able to:

• Recognize a discontinuity

• Identify its correct technical name

• Determine its location

• Measure its size and extent

• Record the indication accurately

• Determine which acceptance criteria apply

• Decide whether it is acceptable or rejectable according to the governing document

AWS currently includes weld and base metal discontinuities among the subjects addressed in its CWI Fundamentals training.

Buy the Latest AWS CWI Exam Self-Study Material Question Bank

Topics Covered in This Practice Test

The 19 questions cover important Chapter 9 subjects, including:

• Discontinuity versus defect

• Weld discontinuity terminology

• Surface and internal discontinuities

• Cracks

• Crater cracks

• Longitudinal cracks

• Transverse cracks

• Toe cracks

• Root cracks

• Underbead and HAZ cracks

• Porosity

• Scattered porosity

• Cluster porosity

• Piping porosity

• Slag and other inclusions

• Incomplete fusion

• Incomplete joint penetration

• Undercut

• Underfill

• Overlap

• Excessive reinforcement

• Excessive convexity

• Concavity

• Arc strikes

• Weld-profile discontinuities

• Laminations

• Seams and laps

• Lamellar tearing

• Causes of welding discontinuities

• Inspection and acceptance principles

AWS training specifically identifies process, metallurgical, base-metal, and structural welding discontinuities as welding-fundamentals subjects.

What Is a Welding Discontinuity?

A discontinuity is an interruption in the typical or uniform structure of a material.

In welding, common discontinuities include:

• Cracks

• Porosity

• Slag inclusions

• Undercut

• Incomplete fusion

• Incomplete joint penetration

• Overlap

• Profile irregularities

The presence of a discontinuity does not automatically mean that the weld must be rejected.

AWS emphasizes the distinction between a discontinuity and a defect: a discontinuity is not necessarily rejectable, while a defect is a condition that fails to meet the applicable acceptance requirements.

This distinction is extremely important for CWI candidates.

Discontinuity vs. Defect

These two terms should not be used interchangeably.

Discontinuity

A discontinuity is an interruption in the normal physical, mechanical, or metallurgical condition of a material or weld.

It may or may not be acceptable.

Defect

A defect is a discontinuity, or combination of discontinuities, that does not satisfy the applicable acceptance criteria.

Therefore:

All defects are discontinuities, but not all discontinuities are defects.

For example, a small amount of porosity might be permitted by a particular code, while a larger amount may exceed the acceptance limit and become rejectable.

The welding inspector should never reject something simply because a discontinuity exists. The applicable code, specification, drawing, or contract must be consulted.

Why Weld Discontinuities Matter

Welding discontinuities can influence the performance of a welded component differently depending on their:

• Type

• Size

• Shape

• Orientation

• Location

• Distribution

• Number

• Service conditions

• Applied stress

• Material properties

A rounded discontinuity and a sharp planar discontinuity do not necessarily have the same significance.

A discontinuity located in a highly stressed region may also be more significant than the same type located elsewhere.

This is why acceptance limits vary among construction codes and applications.

Classification by Location

Welding discontinuities may be located:

At the Surface

Examples include:

• Surface cracks

• Undercut

• Overlap

• Surface porosity

• Underfill

• Arc strikes

• Incorrect weld profile

Below the Surface

Examples may include:

• Incomplete fusion

• Incomplete joint penetration

• Slag inclusions

• Internal porosity

• Subsurface cracks

Some discontinuities can occur either at the surface or internally depending on joint geometry and their location.

Cracks

A crack is a fracture-type discontinuity characterized by a sharp tip and a high ratio of length and width relative to its opening.

Cracks are particularly important because their sharp geometry can produce severe stress concentrations and allow propagation under loading. AWS therefore describes cracks as among the most severe welding discontinuities.

Cracks can be classified according to:

• Location

• Orientation

• Time of occurrence

• Metallurgical mechanism

Common Types of Welding Cracks

AWS welding terminology includes several crack locations and configurations.

Crater Crack

A crater crack occurs in the crater formed at the termination of a weld bead.

It can develop when the arc is stopped without adequately filling the crater.

Possible contributing conditions include:

• Improper arc termination

• Insufficient filler metal at the crater

• High shrinkage stress

• Susceptible weld-metal composition

Proper crater-filling techniques can reduce the risk.

Longitudinal Crack

A longitudinal crack runs approximately parallel to the axis of the weld.

It may occur in:

• Weld metal

• Weld interface

• Heat-affected zone

• Base metal

The exact cause depends on the location, material, welding procedure, stress condition, and time of formation.

Transverse Crack

A transverse crack is oriented approximately perpendicular to the weld axis.

Depending on the situation, it may extend through:

• Weld metal

• HAZ

• Base metal

• Multiple regions

Such cracks can be associated with metallurgical conditions and high restraint.

Toe Crack

A toe crack begins at or near the weld toe.

The weld toe is already a geometric stress concentration, so an actual crack at this location can be significant.

Potential contributing conditions can include:

• High restraint

• Hydrogen

• Hard HAZ

• Poor weld profile

• High residual stresses

Root Crack

A root crack originates at or near the weld root.

Root geometry, incomplete fusion, high restraint, hydrogen, and metallurgical conditions may contribute depending on the application.

Underbead Crack

An underbead crack generally forms in the heat-affected zone beneath or adjacent to the weld.

Hydrogen-assisted cracking is one possible mechanism associated with underbead cracking in susceptible steels.

Important factors may include:

• Diffusible hydrogen

• Hard or susceptible HAZ microstructure

• Tensile stress

• Restraint

• Cooling conditions

Heat-Affected Zone Crack

A HAZ crack occurs in base metal whose properties have been altered by the welding thermal cycle.

HAZ cracking should not be confused with weld-metal cracking because the two occur in different metallurgical regions.

Porosity

Porosity consists of cavity-type discontinuities associated with gas becoming trapped during solidification.

Porosity can occur as:

• Individual pores

• Scattered porosity

• Clustered porosity

• Linear or aligned porosity

• Piping or elongated porosity

The exact terminology and acceptance limits should be taken from the applicable code or standard.

AWS includes porosity among the principal weld discontinuities inspectors are expected to recognize.

Common Causes of Porosity

Possible causes may include:

• Oil or grease

• Moisture

• Rust

• Paint or coatings

• Contaminated filler metal

• Damp consumables

• Inadequate shielding gas

• Excessive shielding-gas flow causing turbulence

• Drafts disturbing the shielding envelope

• Excessive arc length

• Improper welding technique

The inspector should determine the actual cause from the specific process and welding conditions rather than assuming every porosity problem has the same source.

Preventing Porosity

Depending on the welding process, control measures may include:

• Cleaning the joint

• Removing moisture

• Maintaining consumables correctly

• Checking shielding-gas composition

• Checking gas-flow rate

• Protecting the arc from drafts

• Maintaining proper torch angle

• Using appropriate electrical parameters

• Following the approved WPS

A repair should address the underlying cause as well as the visible discontinuity.

Slag Inclusions

A slag inclusion is nonmetallic material trapped within the weld metal or between weld metal and base metal.

Slag-forming processes include:

• SMAW

• FCAW

• SAW

Slag must normally rise to the weld-pool surface during solidification. If it becomes trapped, an inclusion may remain.

Common Causes of Slag Inclusions

Possible causes include:

• Inadequate cleaning between passes

• Improper electrode manipulation

• Incorrect electrode angle

• Narrow groove geometry

• Poor bead placement

• Insufficient heat

• Improper welding parameters

• Slag trapped between adjacent beads

AWS has recently identified incomplete fusion and slag inclusion as recurring quality problems in groove and fillet welding when welding parameters and technique are poorly controlled.

Incomplete Fusion

Incomplete fusion occurs when fusion does not take place between weld metal and base metal or between adjoining weld beads.

It is sometimes casually called “lack of fusion,” although candidates should learn the terminology used by their applicable AWS documents.

Incomplete fusion may occur:

• At a groove face

• Between weld passes

• At the root

• Between weld metal and base metal

AWS lists incomplete fusion among the common discontinuities addressed in its welding inspection material.

Common Causes of Incomplete Fusion

Possible causes include:

• Insufficient welding heat

• Excessive travel speed

• Incorrect electrode angle

• Improper torch manipulation

• Poor joint preparation

• Oxide, slag, scale, or contamination

• Incorrect bead placement

• Improper welding parameters

• Weld pool flowing ahead of the arc

The inspector should compare actual welding variables with the approved WPS when investigating repeated incomplete-fusion problems.

Incomplete Joint Penetration

Incomplete Joint Penetration, commonly abbreviated as IJP, occurs when the weld metal does not extend through the joint thickness or root as required by the specified joint design.

It is important to distinguish this from a Partial Joint Penetration (PJP) weld that is intentionally designed and specified as partial penetration.

A correctly made PJP weld is not automatically a discontinuity simply because it does not penetrate the full joint thickness.

Incomplete joint penetration becomes a concern when the specified joint requires greater penetration than was actually achieved.

Causes of Incomplete Joint Penetration

Possible causes include:

• Root opening too small

• Root face too large

• Incorrect groove angle

• Misalignment

• Insufficient current

• Excessive travel speed

• Electrode too large for the joint

• Poor electrode access

• Incorrect electrode placement

• Improper joint preparation

AWS includes incomplete joint penetration among the principal discontinuities addressed in its weld-discontinuity guidance.

Incomplete Fusion vs. Incomplete Joint Penetration

This distinction is important for AWS CWI Part A questions.

Incomplete Fusion

Fusion failed between surfaces that were intended to fuse.

It may occur between:

• Weld and base metal

• Adjacent weld passes

Incomplete Joint Penetration

The weld failed to penetrate to the required depth at the joint root.

Therefore:

Fusion describes bonding between surfaces. Penetration describes how far the weld extends into or through the joint.

Do not automatically treat these terms as interchangeable.

Undercut

Undercut is a groove melted into the base metal adjacent to the weld toe or weld root and left unfilled by weld metal.

It can reduce the effective base-metal cross-section and create a stress concentration.

Possible contributing conditions include:

• Excessive welding current

• Excessive travel speed

• Long arc length

• Incorrect electrode angle

• Poor manipulation

• Improper voltage

AWS includes undercut among common discontinuities that welding inspectors should recognize during visual inspection.

Undercut Acceptance

Not every amount of undercut is automatically rejectable.

The inspector should measure:

• Depth

• Length

• Location

• Distribution

The result must then be compared with the applicable acceptance criteria.

The allowable amount can differ according to:

• Code

• Loading condition

• Material thickness

• Weld orientation

• Service application

Never create an acceptance limit from memory when the governing document is available.

Underfill

Underfill occurs when the surface of a weld is below the adjacent surface of the base metal.

It may occur on the:

• Weld face

• Weld root

Underfill can result in insufficient weld cross-section and may reduce the thickness available to carry load.

Possible causes include:

• Insufficient filler-metal deposition

• Excessive travel speed

• Improper technique

• Incorrect parameters

Underfill should not be confused with undercut.

Undercut vs. Underfill

Undercut

A groove has been melted into the base metal adjacent to the weld and has not been completely filled.

Underfill

The weld surface itself lies below the adjacent base-metal surface.

Candidates should identify the exact location of the missing material before selecting an answer.

---

Overlap

Overlap occurs when weld metal extends beyond the weld toe or root onto the adjacent base-metal surface without proper fusion.

It often produces a rolled-over or protruding appearance.

Potential contributing causes include:

• Insufficient travel speed

• Excessive filler-metal deposition

• Incorrect electrode angle

• Improper manipulation

• Incorrect welding parameters

Overlap should not be confused with excessive reinforcement. The important distinguishing feature is weld metal extending beyond the fusion boundary without adequate fusion.

AWS lists overlap among the core discontinuity types covered in its visual inspection material.

Weld Profile Discontinuities

Welding inspectors should evaluate more than internal soundness.

AWS currently describes dimensional or profile-related discontinuities as conditions involving the shape, size, or contour of a weld. Examples can include excessive reinforcement, incorrect weld size, overlap, undercut, spatter, convexity, and other incorrect profiles.

Profile conditions may include:

• Excessive convexity

• Excessive concavity

• Excessive reinforcement

• Insufficient reinforcement

• Incorrect weld size

• Irregular bead profile

• Excessive asymmetry

Acceptance depends on the applicable code or specification.

Excessive Convexity

Convexity describes the outward curvature of a fillet-weld face.

Some convexity may naturally occur, but excessive convexity can:

• Increase weld-metal volume unnecessarily

• Create an abrupt transition at the weld toe

• Increase stress concentration

• Indicate poor welding technique

The permissible profile must be determined from the governing requirements.

Concavity

A concave fillet weld has a face that curves inward.

Concavity does not automatically mean the weld is undersized.

The inspector must determine whether the required effective size or throat has been achieved according to the governing document.

Excessive Reinforcement

Weld reinforcement is weld metal extending above the surface of the base metal in a groove weld.

Some reinforcement may be permitted.

Excessive reinforcement may create:

• Poor transition

• Stress concentration

• Unnecessary weld-metal volume

• Difficulty meeting profile requirements

The inspector should measure the actual condition rather than judging it by appearance alone.

Arc Strikes

An arc strike is a localized area where an arc has been accidentally or intentionally initiated outside the intended weld area.

An arc strike can produce:

• Local melting

• Rapid heating and cooling

• Local hardness changes

• Surface blemishes

• Cracking in susceptible materials

The inspector should follow the governing code or project requirements for examination and correction of arc strikes.

Spatter

Spatter consists of small particles of molten metal expelled during welding that adhere to or land near the weld.

Excessive spatter may indicate:

• Incorrect welding parameters

• Incorrect polarity

• Excessive arc length

• Poor shielding

• Unstable metal transfer

• Process or technique problems

Spatter is not automatically rejectable under every welding code. Acceptance and required cleanup depend on the applicable project requirements.

Base Metal Discontinuities

Not every discontinuity found during welding inspection originates from welding.

Base metal can contain discontinuities resulting from:

• Steelmaking

• Casting

• Rolling

• Forging

• Forming

• Cutting

• Handling

• Previous fabrication

The inspector should therefore examine base material before welding begins whenever required.

Important base-metal discontinuities include:

• Laminations

• Seams

• Laps

• Cracks

• Lamellar tearing

• Gouges and other surface damage

Laminations

A lamination is a planar base-metal discontinuity commonly oriented approximately parallel to the rolled surface.

Laminations can originate from conditions present during material manufacture and rolling.

They may become visible when:

• Plate edges are cut

• A groove is prepared

• Material is machined

• Ultrasonic examination is performed

A lamination should not automatically be repaired or rejected without consulting the applicable material and fabrication requirements.

Seams and Laps

Seams and laps are elongated surface or near-surface discontinuities that may originate during manufacturing processes such as rolling or forming.

Their significance depends on:

• Depth

• Orientation

• Location

• Material specification

• Final service

• Applicable acceptance criteria

Welding over an unacceptable base-metal discontinuity can create additional problems, so significant conditions should be resolved before welding proceeds.

Lamellar Tearing

Lamellar tearing occurs in base metal, generally adjacent to a weld, as a result of through-thickness strain acting on susceptible rolled material.

The condition is associated with:

• Through-thickness shrinkage stress

• Joint restraint

• Nonmetallic inclusions

• Poor through-thickness ductility

• Certain joint configurations

The tears often run approximately parallel to the plate surface with a characteristic stepped appearance.

Control may involve engineered changes such as:

• Different joint design

• Material with improved through-thickness properties

• Reduced restraint

• Buttering

• Modified welding sequence

The welding inspector should not independently redesign a connection. Any preventive or repair change must follow approved engineering requirements.

Discontinuity Causes: Three Areas to Consider

When a discontinuity is repeatedly occurring, inspectors should consider more than just welder technique.

1. Process-Related Causes

Examples:

• Incorrect amperage

• Incorrect voltage

• Excessive travel speed

• Poor shielding

• Wrong polarity

• Incorrect electrode angle

• Poor bead placement

2. Material and Metallurgical Causes

Examples:

• High hardenability

• Hydrogen

• Unfavorable cooling rate

• Base-metal inclusions

• Susceptible microstructure

• Incorrect filler material

3. Fabrication Causes

Examples:

• Incorrect root opening

• Excessive root face

• Poor alignment

• Contaminated joint

• Excessive restraint

• Poor access

• Inadequate cleaning between passes

AWS Fundamentals training similarly separates process, metallurgical, base-metal, and structural discontinuities when teaching their causes.

Discontinuity Acceptance Criteria

A discontinuity should be evaluated using the applicable governing document.

Depending on the code, acceptance may consider:

• Type

• Length

• Width

• Depth

• Number

• Spacing

• Distribution

• Orientation

• Location

• Accumulated length

For example, the allowable amount of porosity or undercut may differ substantially between different codes and service applications.

The welding inspector’s responsibility is to:

1. Identify the condition correctly.

2. Measure it accurately.

3. Locate the applicable requirement.

4. Compare the result with the acceptance criteria.

5. Record the inspection result.

Appearance alone is not a reliable basis for determining weld acceptability. AWS visual-inspection guidance emphasizes comparing the actual condition with specified requirements.

Surface vs. Volumetric vs. Planar Discontinuities

For examination purposes, it is helpful to understand the general geometry of discontinuities.

Planar Discontinuities

Planar conditions have relatively small thickness compared with their length and width.

Examples can include:

• Cracks

• Incomplete fusion

• Some laminations

• Lamellar tears

Their sharp edges or crack-like geometry may create significant stress concentration.

Volumetric Discontinuities

Volumetric discontinuities occupy a three-dimensional volume.

Examples can include:

• Porosity

• Slag inclusions

The actual significance of either type still depends on the governing acceptance criteria.

Inspection Methods for Common Discontinuities

Different inspection methods have different capabilities.

Visual Testing

Useful for detecting visible surface conditions such as:

• Undercut

• Overlap

• Surface cracks

• Surface porosity

• Incorrect profile

• Incorrect weld size

Liquid Penetrant Testing

Useful for detecting discontinuities open to the surface in suitable nonporous materials.

Magnetic Particle Testing

Useful for detecting surface and near-surface discontinuities in ferromagnetic materials.

Radiographic Testing

Commonly useful for detecting volumetric discontinuities and certain internal conditions depending on orientation and technique.

Ultrasonic Testing

Useful for detecting and locating many internal discontinuities, particularly when their orientation is favorable to the sound beam.

Chapter 10 of WIT provides the more detailed treatment of visual inspection and other NDE methods; Chapter 9 primarily builds the candidate’s ability to recognize and understand the discontinuities being sought. AWS visual-inspection guidance also stresses that inspectors need correct terminology to describe the nature, location, and extent of discovered discontinuities.

Welding Inspector Responsibilities

Before Welding

The inspector may verify:

• Base-metal condition

• Material identification

• Joint preparation

• Root opening

• Root face

• Groove angle

• Alignment

• Surface cleanliness

• Existing laminations or surface defects

• Approved WPS

• Correct consumables

During Welding

The inspector may observe:

• Welding parameters

• Shielding

• Electrode handling

• Interpass cleaning

• Joint accessibility

• Bead placement

• Preheat

• Interpass temperature

• Crater filling

• Weld sequence

After Welding

The inspector may check:

• Cracks

• Porosity

• Undercut

• Overlap

• Underfill

• Weld size

• Weld profile

• Reinforcement

• Arc strikes

• Dimensional compliance

• Required NDE results

Any discontinuity should be properly identified, measured, documented, and evaluated using the applicable criteria.

Common CWI Exam Mistakes to Avoid

Candidates should avoid these frequent mistakes:

1. Assuming every discontinuity is a defect

2. Calling every discontinuity a crack

3. Confusing incomplete fusion with incomplete penetration

4. Confusing undercut with underfill

5. Confusing overlap with excessive reinforcement

6. Treating a specified PJP weld as incomplete penetration

7. Assuming all porosity is automatically rejectable

8. Guessing acceptance criteria from appearance

9. Confusing weld-metal cracks with HAZ cracks

10. Assuming a base-metal lamination was caused by welding

11. Confusing lamination with lamellar tearing

12. Ignoring the location of a discontinuity

13. Ignoring discontinuity orientation

14. Calling weld profile a purely cosmetic issue

15. Assuming all arc strikes are acceptable

16. Ignoring cleaning between passes as a cause of slag inclusions

17. Treating visual inspection as sufficient for every internal condition

18. Using the words defect and discontinuity interchangeably

19. Repairing a discontinuity without first determining the governing requirements

Key Differences to Remember

Discontinuity vs. Defect

Discontinuity: An interruption in normal material or weld structure that may or may not be acceptable.

Defect: A discontinuity that fails to satisfy the applicable acceptance requirements.

Incomplete Fusion vs. Incomplete Joint Penetration

Incomplete fusion: Required fusion between surfaces was not achieved.

Incomplete joint penetration: The weld did not penetrate to the required depth at the joint root.

Undercut vs. Underfill

Undercut: Groove melted into adjacent base metal and left unfilled.

Underfill: Weld surface lies below the adjacent base-metal surface.

Overlap vs. Reinforcement

Overlap: Weld metal extends beyond the weld boundary without proper fusion.

Reinforcement: Weld metal properly fused but projecting above the base-metal surface.

Lamination vs. Lamellar Tearing

Lamination: Base-metal discontinuity generally originating during material manufacture.

Lamellar tearing: Base-metal tearing associated with welding-induced through-thickness strain in susceptible material.

How to Answer Discontinuity Questions

Use this simple method during the test.

Step 1 – Identify the Location

Is the condition in:

• Weld metal?

• HAZ?

• Base metal?

• Weld toe?

• Root?

• Groove face?

Step 2 – Identify the Shape

Is it:

• Linear?

• Rounded?

• Planar?

• Volumetric?

• Groove-like?

• Rolled-over?

Step 3 – Identify the Mechanism

Ask whether the condition is related to:

• Gas

• Slag

• Fusion

• Penetration

• Shrinkage

• Hydrogen

• Welding technique

• Base-metal manufacture

Step 4 – Select the Correct Technical Term

Do not choose an answer merely because two discontinuities look similar.

Step 5 – Separate Identification from Acceptance

First determine what the discontinuity is.

Then determine whether it is acceptable according to the applicable criteria.

Start the AWS CWI Part A WIT Chapter 9 Practice Test

Test your knowledge of Weld and Base Metal Discontinuities with these 19 multiple-choice questions.

Pay particular attention to:

• Discontinuity

• Defect

• Crack

• Porosity

• Inclusion

• Incomplete fusion

• Incomplete penetration

• Undercut

• Underfill

• Overlap

• Reinforcement

• Lamination

• Lamellar tearing

• Weld profile

• Acceptance criteria

Start the free AWS CWI Part A WIT Chapter 9 practice test now.

What This Free Practice Test Includes

This chapter-wise practice test provides:

• 19 multiple-choice questions

• Four options for every question

• Correct answers

• Clear technical explanations

• Weld-discontinuity identification

• Base-metal discontinuity questions

• Crack terminology

• Porosity questions

• Fusion and penetration questions

• Weld-profile questions

• Acceptance-principle questions

• Immediate online access

• Mobile-friendly preparation

• Free AWS CWI study support

How to Prepare for WIT Chapter 9

For effective preparation:

1. Understand the difference between a discontinuity and a defect.

2. Learn common AWS crack terminology.

3. Study the different forms of porosity.

4. Learn the causes of slag inclusions.

5. Compare incomplete fusion and incomplete joint penetration.

6. Compare undercut and underfill.

7. Learn how overlap develops.

8. Review acceptable weld-profile terminology.

9. Study arc strikes.

10. Learn base-metal laminations, seams, and laps.

11. Understand lamellar tearing.

12. Study the effect of joint preparation on discontinuities.

13. Review the effect of welding parameters.

14. Learn which discontinuities are surface or internal.

15. Understand planar versus volumetric discontinuities.

16. Practice identifying discontinuities from drawings and photographs.

17. Always separate discontinuity identification from code acceptance.

18. Review every incorrect explanation.

19. Retake all 19 questions after revision.

Important Disclaimer

UpWeld is an independent educational platform and is not affiliated with, sponsored by, endorsed by, or officially connected with the American Welding Society.

“American Welding Society,” “AWS,” “CWI,” “CAWI,” and related certification names may be trademarks of their respective owners.

The questions and explanations on this page are independently prepared for educational and examination-practice purposes. They are not actual AWS certification examination questions.

Acceptance criteria for cracks, porosity, inclusions, undercut, incomplete fusion, penetration, weld profile, and base-metal discontinuities vary according to the applicable code, material, structure, service condition, loading, and project specification.

Always use the governing code, approved drawings, specifications, WPS, and contractual requirements when making an actual inspection decision.

Conclusion

Recognizing welding discontinuities is a fundamental skill for every welding inspector.

A competent inspector should be able to distinguish a crack from incomplete fusion, incomplete fusion from incomplete penetration, undercut from underfill, overlap from reinforcement, and a base-metal lamination from a welding-related discontinuity.

Equally important is understanding that a discontinuity is not automatically a defect. Acceptance or rejection must be based on the applicable governing criteria.

Complete all 19 AWS CWI Part A WIT Chapter 9 Questions and Answers, carefully review each explanation, and repeat the test after revising any topic you find difficult.

After completing Chapter 9, continue with AWS CWI Part A – WIT Chapter 10: Visual Inspection and Other NDE Methods and Symbols.

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• AWS CWI Exam Preparation Materials

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