Wow, TIL. This has some details at "5 year old level:" https://www.quora.com/What-is-the-difference-between-iron-and-steel https://www.quora.com/What-is-the-di

Wow, TIL. This has some details at "5 year old level:" https://www.quora.com/What-is-the-difference-between-iron-and-steel https://www.quora.com/What-is-the-difference-between-iron-an... The phase diagram is very interesting too. Very little carbon is needed to go from elemental iron to steel, looks like about 0.008%. Thanks for posting that!