Welding Inspection & Metallurgy API ICP Self Study Notes

3.12 burn-through: A non-standard term for excessive visible root
reinforcement in a joint welded from one side or a hole through the root bead.
Also, a common term used to reflect the act of penetrating a thin component
with the welding arc while hot tap welding or in-service welding.
3.13 constant current power supply: An arc welding power source with a
volt-ampere relationship yielding a small welding current change from a
large arc voltage change.
3.14 constant voltage power supply: An arc welding power source with a
volt-ampere relationship yielding a large welding current change from a
small voltage change.
3.15 crack: A fracture type discontinuity characterized by a sharp tip and
high ratio of length and width to opening displacement.