Welding Inspection & Metallurgy API ICP Self Study Notes

10.2.3 Welding Metallurgy
Welding metallurgy is concerned with;
• melting,
• solidification,
• gas-metal reactions,
• slag-metal reactions,
• surface phenomena and
• base metal reactions.
These reactions occur very rapidly during welding due to the rapid changes in
temperature caused by the welding process. This is in contrast to metallurgy
of castings, which tends to be slower and often more controlled. The parts of
a weld comprises three zones, (1) the weld metal, (2)heat-affected metal
(zone), and (3) base metal.