CSWIP 3.1 QUESTION AND ANSWER SERIES
1) When welding medium carbon steel plates over 90mm in thickness would the basic electrode require any pre-treatment before use?
|a. ( answer )||None if they were in a vacuum pack|
|b.||None if they were used in a factory|
|c.||Heat to 500oC for 2 hours if used outside|
|d.||Baked at 150oC for 4 hours prior to use|
2) An advantage of the MMA (111) welding process is that if:
|a.||Has higher current density than SAW (121) welding|
|b. ( answer )||Has a very large range of consumable for most welding applications|
|c.||No core wire is lost during the process|
|d.||Requires a lower skill level than other manual forms of welding|
3) Rutile electrodes are often sold packed in a cardboard box covered with a plastic film … you found they were damp and the ends were rusty what course of action would you …
|a.||Use them as rutile electrodes are only for general purpose welding|
|b.||Re-dry them at 125oC and issue to the shop floor|
|c. ( answer )||Quarantine them|
|d.||Only use them for tack welding|
- Rutile electrodes do not require pre-baking but should be stored in a dry condition.
- Checks should be made to ensure that the correct specification of electrode is being used, the electrode is the correct diameter and in good condition.
- Rutile electrodes can be dried to lower H2 content but cannot be baked as it will destroy the coating.
4) Which of the following defects are not associated with the MMA (SMAW) welding process?
|b.||Lack of fusion|
|d. ( answer )||Tungsten inclusions|
Inclusions – Tungsten:
Causes: Contamination of weld Caused by tungsten touching weld metal or parent metal during welding using the TIG welding process
5) Slag lines found in MMA welds are usually associated with:
|a.||The voltage being too low|
|b.||The open circuit current being too high|
|c.||Improper cleaning between weld runs|
|d.||Low open circuit voltage|
Inclusions – Slag:
6) When MMA welding what will be the effect on the weld if the electrode was channged from AC to DC-ve?
|b.||Lower deposition rate|
|c. ( answer )||It would be less penetration or a slight increase in deposition rate|
|d.||The arc would become unstable|
7) Which of the following electrodes don’t require re-baking at higher temperature …
|b. ( answer )||Vacuum packed types|
8) Using the MMA process, which polarity produces the greatest penetration?
|c. (answer )||DC+|
|d.||Depends on electrode size|
9) When welding vertically up with the MMA process weaving is sometimes restricted diameter, this restriction is mainly applied to:
|a.||Reduce the overall width of the weld|
|b. ( answer )||Limit the heat input into the joint|
|c.||Reduce the number of electrodes used in the joint|
|d.||Reduce the time required to finish the weld|
The weaving will effect to ROL –> chagne Heat Input.
10) A typical baking temperature for basic low hydrogen electrodes is: