How is steel made strong?
Iron's Tough Lesson
How is steel made strong?
Steel is everywhere — bridges, buildings, train tracks, giant ships crossing oceans. It holds up our world. But here's the weird part: pure iron is soft. You could bend it with your hands like a paperclip. So how does iron become steel, and how does steel get strong enough to hold up a skyscraper?
It starts in a blast furnace — a tower as tall as a building, roaring with heat. Workers dump iron ore, coke (a super-hot-burning coal), and limestone into the top. At the bottom, temperatures hit 3,000°F. The iron melts and drips down like a glowing river, while impurities float away as slag. What pours out is molten iron, orange and liquid as lava.
