8.1 State THREE welding aspects that must be focused on during the arc welding procedure - NSC Mechanical Technology Welding and Metalwork - Question 8 - 2021 - Paper 1

1. Aiming at a width to depth ratio of 1:1.
2. Decreasing the welding current to prevent excess penetration.

8.3.1 Lack of fusion:

1. Travel speed is too slow.
2. Weld joint is wide.

8.3.2 Porosity:

1. Contaminated weld surface.
2. Wet or dirty electrodes.

8.3.3 Incomplete penetration:

1. Welding current too low.
2. Electrode too big.

1. Open the acetylene torch valve ¼ turns or less and ignite.
2. Adjust the acetylene torch valve until the black smoke disappears.
3. Open the oxygen torch valve until the flame is no longer burning yellow.

1. Specimen is placed across the supports of the die.
2. Apply force to the specimen to bend into the shape of the die.
3. Determine the percentage of elongation of the welded metal.

1. Determine the ductility of the weld.
2. Determine the percentage of elongation of the weld metal.

1. Type A: Fluorescent that emits visible light when viewed using a black light.
2. Type B: Brightly colored liquid dyes that can be inspected in regular light.

The nick-break test determines internal quality of the weld and reveals internal defects such as slag inclusions, porosity, and lack of fusion.