FCAW Defects and Troubleshooting: Master Common Issues and Solutions

Question 1

In FCAW, which defect is identified by a groove-like depression along the weld's edge?

Accepted Answer

Undercut

Answer

Porosity

Answer

Slag Inclusions

Answer

Cold Laps

Question 2

Which of the following defects is caused by welding too quickly?

Accepted Answer

Undercut

Answer

Lack of penetration

Answer

Porosity

Answer

Cold lap

Question 3

What is the main purpose of the flux in Flux-Cored Arc Welding (FCAW)?

Accepted Answer

To protect the weld pool from the atmosphere

Answer

To add alloying elements to the weld metal

Answer

To stabilize the arc

Answer

To remove impurities from the weld metal

Question 4

How can slag inclusions be prevented in FCAW?

Accepted Answer

Cleaning the workpiece before welding

Answer

Using a lower voltage setting

Answer

Increasing the travel speed

Answer

Decreasing the amperage

Question 5

What is a key advantage of using a flux-cored electrode over a solid electrode?

Accepted Answer

Higher deposition rate

Answer

Deeper penetration

Answer

Reduced spatter

Answer

Improved weld quality

Question 6

Which of the following is NOT a characteristic of cold lap defects?

Accepted Answer

Uniform weld bead appearance

Answer

Lack of fusion between weld passes

Answer

Reduced joint strength

Answer

Prominent surface irregularities

Question 7

What type of defect is characterized by excessive weld metal buildup on one side of the joint, creating an uneven surface?

Accepted Answer

Overlap

Answer

Undercut

Answer

Burn-through

Answer

Cold lap

Question 8

Slag inclusions in FCAW welds can weaken the weld's:

Accepted Answer

Strength

Answer

Appearance

Answer

Flexibility

Question 9

Which gas mixture is commonly used in FCAW to prevent porosity and improve weld quality?

Accepted Answer

Carbon Dioxide-Oxygen (CO₂-O₂)

Answer

Argon-Oxygen

Answer

Nitrogen-Helium

Answer

Argon-Hydrogen

Question 10

What type of defect is caused by the presence of small, spherical voids within the weld metal?

Accepted Answer

Porosity

Answer

Cracking

Answer

Lack of fusion

Answer

Undercut

Question 11

What is the primary purpose of using a backing plate in FCAW?

Accepted Answer

To prevent burn-through

Answer

To provide additional support to the weld

Answer

To improve weld penetration

Answer

To reduce distortion

Question 12

What is the recommended approach to determine the appropriate travel speed for FCAW?

Accepted Answer

It depends on the material thickness

Answer

As fast as possible

Answer

As slow as possible

Answer

It depends on the welder's skill level

Question 13

Which of the following is a characteristic of a weld joint with lack of fusion?

Accepted Answer

Reduced strength and ductility

Answer

Smooth and uniform surface

Answer

Excessive weld reinforcement

Answer

Minimal slag inclusions

Question 14

Which safety precaution is **most** important to take when welding with FCAW to prevent electric shock?

Accepted Answer

Ground the workpiece properly

Answer

Wear insulated gloves and clothing

Answer

Use a welding helmet

Answer

Keep welding cables away from water

Question 15

What is the recommended shielding gas for FCAW of mild steel?

Accepted Answer

Argon-carbon dioxide mixture

Answer

Pure argon

Answer

Pure helium

Answer

Nitrogen

Question 16

What is the primary function of the contact tip in FCAW?

Accepted Answer

To provide electrical contact between the wire and the welding machine

Answer

To guide the wire to the weld area

Answer

To shield the weld from the atmosphere

Answer

To control the flow of shielding gas

Question 17

In FCAW, how does excessive welding speed contribute to undercut defects?

Accepted Answer

Excessive speed prevents the weld pool from flowing into the joint, causing a lack of fusion and undercut.

Answer

Excessive speed increases heat input, causing the weld metal to melt and flow out of the joint, resulting in undercut.

Answer

Excessive speed has no impact on undercut defects.

Answer

Excessive speed fills undercut defects by providing more molten metal to the joint.

Question 18

How does the flux in FCAW help create a cleaner weld by preventing slag inclusions?

Accepted Answer

It reacts with impurities, forming a protective slag layer that floats on the molten metal, preventing slag from getting trapped.

Answer

It forms a gas shield that stops oxygen from reacting with the molten metal.

Answer

It acts as a lubricant, reducing friction between the welding wire and the workpiece to minimize slag formation.

Answer

It increases the fluidity of the molten metal, allowing slag to flow away from the weld area.

Question 19

How does moisture in the shielding gas contribute to porosity in FCAW?

Accepted Answer

Reacts with the molten weld pool, forming hydrogen gas that causes porosity

Answer

Causes hydrogen embrittlement

Answer

Increases the surface tension of the weld pool

Answer

Prevents slag formation

Question 20

What is the primary function of shielding gas in FCAW?

Accepted Answer

Protection of the weld pool from atmospheric gases

Answer

Increase in welding current

Answer

Enhancement of weld penetration

Answer

Reduction of welding spatter

Question 21

For welding high-strength steels, which type of FCAW wire is recommended?

Accepted Answer

Metal-cored wire

Answer

Gas-shielded wire

Answer

Solid-cored wire

Answer

Self-shielded wire

Question 22

What is the benefit of slag formation in FCAW?

Accepted Answer

Protection of the weld pool from oxidation

Answer

Reduced welding spatter

Answer

Increased weld strength

Answer

Improved weld bead appearance

Question 23

How can undercut be visually detected in FCAW welds?

Accepted Answer

Examination of the weld bead profile

Answer

Magnetic particle testing

Answer

Ultrasonic testing

Answer

Radiographic inspection

Question 24

What is the primary cause of porosity in FCAW?

Accepted Answer

Insufficient shielding gas flow

Answer

Improper wire feed speed

Answer

Excessive welding current

Answer

Excessive shielding gas flow

Question 25

Which of the following is a common cause of excessive spatter in FCAW?

Accepted Answer

Contaminated shielding gas

Answer

Proper shielding gas flow

Answer

Correct welding parameters

Answer

Clean work surface

Question 26

What is the main purpose of using a flux-cored wire in FCAW?

Accepted Answer

To provide shielding gas and filler metal simultaneously

Answer

To increase welding speed

Answer

To improve weld penetration

Question 27

What is the primary cause of porosity in FCAW?

Accepted Answer

Entrapped gas

Answer

Incorrect welding parameters

Answer

Improper joint preparation

Answer

Impurities in the wire

Question 28

Which of the following is a consequence of excessive slag inclusion in FCAW welds?

Accepted Answer

Reduced weld strength

Answer

Enhanced weld appearance

Answer

Improved corrosion resistance

Question 29

What is the first step in troubleshooting FCAW defects?

Accepted Answer

Identify the type of defect

Answer

Adjust welding parameters

Answer

Replace consumables

Answer

Inspect equipment

Question 30

Which of the following tools is recommended for inspecting weld defects?

Accepted Answer

Magnifying glass

Answer

Flux core guide

Answer

Tackle

Answer

Weld gauge

Question 31

What is the purpose of using a low-speed grinder with a fine-grit wheel to repair defects in FCAW welds?

Accepted Answer

To minimize the risk of damaging the weld base metal

Answer

To grind the defect to a specific depth

Answer

To improve the surface finish of the weld

Answer

To remove defects quickly and efficiently

Question 32

What is the primary role of flux in FCAW?

Accepted Answer

To provide shielding gas and slag formation

Answer

To increase weld penetration

Answer

To improve weld appearance

Answer

To reduce spatter

Question 33

What is a key function of a slag conditioner in FCAW?

Accepted Answer

To improve weld appearance and reduce porosity

Answer

To enhance the strength of the weld

Answer

To increase penetration depth

Answer

To prevent spatter

Question 34

What type of electrode is suitable for welding thick, high-strength steel in FCAW?

Accepted Answer

E81T-1/4C-Ni1

Answer

E7018

Answer

E6010

Answer

E308

Question 35

What is the purpose of burn-back in FCAW?

Accepted Answer

To remove excess flux and improve weld penetration

Answer

To reduce the risk of porosity

Answer

To prevent cold lap defects

Question 36

To mitigate spatter formation during FCAW, which of the following techniques is commonly employed?

Accepted Answer

Utilizing an anti-spatter spray

Answer

Reducing the travel speed

Answer

Increasing the wire feed rate

Answer

Using a shielding gas with a higher CO2 content

Question 37

Which weld defect is characterized by the absence of fusion between the weld bead and the base metal?

Accepted Answer

Cold lap

Answer

Porosity

Answer

Undercut

Answer

Burn-through

Question 38

What is the primary function of flux-cored wire in FCAW?

Accepted Answer

To provide both shielding gas and alloying elements

Answer

To increase the welding speed

Answer

To reduce the formation of spatter

Answer

To enhance weld penetration

Question 39

When welding mild steel using FCAW, which shielding gas composition is generally recommended?

Accepted Answer

75% Argon, 25% CO2

Answer

50% Argon, 50% Oxygen

Answer

100% CO2

Answer

100% Argon

Question 40

What is the primary purpose of employing a backing plate in FCAW?

Accepted Answer

To prevent root porosity and oxidation

Answer

To increase the weld strength

Answer

To improve weld appearance

Answer

To reduce weld distortion

Question 41

Which of the following factors is a major contributor to burn-through in FCAW?

Accepted Answer

Excessive welding current

Answer

Incorrect weld angle

Answer

Insufficient shielding gas flow

Answer

Loose contact tip