45.4 OTHER TOPICS
45.4.1 Furnaces
Some of the types include,
- coreless induction - magnetic fields induce eddy currents throughout the entire furnace, resulting in melting
- core induction - magnetic fields induce eddy currents in a small section of the furnace, resulting in melting
- gas fired crucible - uses ignited gas and air to heat crucible in enclosed oven
- electric arc - arcs are used to heat metals
- cupolas - layers of metal and ore are placed in this refractory lined vessel, and ignited to produce large volumes of metal.
45.4.2 Inspection of Casting
General problems with castings are,
Typical inspection methods are,
- polishers & microscopes to look at microscopic structures
- metal analyzer to determine chemical composition
- X-rays are used to examine hidden cracks and blowholes
