Photo AI
8.1 State FOUR uses of a welding gauge - NSC Mechanical Technology Welding and Metalwork - Question 8 - 2022 - Paper 1
Question 8
8.1 State FOUR uses of a welding gauge. 8.2 State TWO causes of EACH of the following welding defects: 8.2.1 Incomplete penetration 8.2.2 Welding spatter 8.3 Sta... show full transcript
Worked Solution & Example Answer:8.1 State FOUR uses of a welding gauge - NSC Mechanical Technology Welding and Metalwork - Question 8 - 2022 - Paper 1
Step 1
State FOUR uses of a welding gauge.
Answer
A welding gauge is primarily used for several purposes:
- Angle of Preparation: It helps in checking the correct angle of preparation for the weld joint.
- Weld Alignment: Ensures that the alignment between different parts to be welded is proper.
- Fillet Weld Leg Length/Dimensions: Used to verify if the fillet weld dimensions comply with the specifications.
- Excess Weld Metal: Assesses if there is excessive weld metal that could affect the integrity of the joint.
Step 2
State TWO causes of EACH of the following welding defects: Incomplete penetration.
Answer
The causes of incomplete penetration in welding include:
- Too Low Welding Current/Amperage: Insufficient current can cause a lack of penetration.
- Incorrect Root Angle: A wrong angle at the joint can prevent proper penetration.
Step 3
State TWO causes of EACH of the following welding defects: Welding spatter.
Answer
Welding spatter may result from:
- Disturbance in the Molten Weld Pool: Any disturbances can lead to splatter during the welding process.
- Too High Welding Current/Amperage: Excessive current can cause molten metal to be ejected from the weld pool.
Step 4
State TWO preventative measures for EACH of the following welding defects: Porosity.
Answer
To prevent porosity, it is essential to:
- Clean the Welding Surface: Ensure that the surfaces to be welded are free from contaminants like rust or oil.
- Ensure that Arc Welding Electrodes are Dry: Moisture on electrodes can lead to trapped gas in the weld.
Step 5
State TWO preventative measures for EACH of the following welding defects: Undercutting.
Answer
Preventative measures for undercutting include:
- Maintain Correct Arc Travel Speed: This ensures that the weld metal is deposited correctly without undermining the base metal.
- Using Correct Arc Voltage: Proper voltage settings can help in reducing the chances of undercutting during the process.
Step 6
Step 7
Step 8
Describe the process of conducting a nick-break test on a welded joint.
Answer
To conduct a nick-break test:
- Prepare the Specimen: Make a cut along both edges, through the center of the weld.
- Support the Specimen: Place the specimen on two supports or a bench to apply controlled force.
- Apply Force: Use a sledging hammer or other means to break the specimen in the area of the cuts.
- Inspect the Break: Examine the exposed metal for incomplete fusion, lack of penetration, and other weld defects to evaluate the integrity of the weld.