Welding Inspection & Metallurgy API ICP Self Study Notes

10.3.3 Electrical Conductivity
The electrical conductivity of a material is a measure of its efficiency in
conducting electrical current. Metals are good conductors of electricity. Metals
that have high electrical conductivity are more efficient in conducting electrical
current than those with a low electrical conductivity. Aluminum and copper
have high electrical conductivity as compared to iron and steel. Their
electrical resistance is also much lower, and as a result, less heat is
generated in the process of carrying an electrical current. This is one of the
reasons that copper and aluminum are used in electric wiring and cables. The
ability of steel to carry an electrical current is much less efficient and more
heat is produced by its high measure of electrical resistance. One can then
deduce that steel can be heated with lower heat inputs than that necessary
for aluminum or copper because of its lower measure of electrical conductivity
and higher electrical resistance.