1. Circuit

Step-down Transformer

Converts high voltage AC to a lower voltage (220V to 80V-100V). This means the
output current is greater than the input current. This is due to the primary coil having
more windings than the secondary coil.... (More)

• Oxy-Acetylene is a Fusion welding process.
• The joint edges are heated until the metals melt.
• The molten metals join and fuse.
• Oxidation is prevented by the envelope of products of combustion.

1. Acetylene

Acetylene would explode if directly compressed. Instead... (More)

Submerged Arc Welding

• Uses bare wire electrode.
• Fed automatically from spool.
• Generates electric arc to heat metal/
• Flux in powder form.
• Fed using a hopper.
• Electric arc melts joint, flux and electrode.
• Excess flux is collected and re-used.
• Fully automated... (More)

Lower Critical Point

• Occurs at 723°c.
• Temperature change occurs.
• The metal contracts dimensionally, glows less brightly and loses its magnetism.
• Known as Decalescence.

Upper Critical Point

• Varies depending on amount of carbon in the steel.
• Above this point, the metal... (More)