Beakman explains what metals are and how they occur naturally. He then pretends to be Andrew Carnegie to explain how he figured out how to make steel. Beakman explains that steel is a lot stronger than iron so this allowed us to create buildings, strong machines, etc.
The Fantastic Four are battling Dr. Doom, who has turned into an organic metal capable of absorbing and manipulating electrical energy. They win the battle by exposing him to excessive heat and then cooling him down rapidly with water, turning him into a solid piece of metal.