STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!

Steel is used in the construction of large and heavy structures, giving POSCO this kind of impression. Other than the child who sent this question, perhaps a lot of people think this way too since POSCO Newsroom has been getting many questions regarding large steel used in buildings and cars.

Let’s see where steel is used. From high bars at playgrounds to skyscrapers, running cars and trains, steel bridges, and ships, most of them are considered heavy and square, giving them a chilly look. So it is a common belief that steel goes by this impression too. But actually, this doesn’t go to all of them. Steel can be large and heavy, but at the same time small and light!

l Overcoming Gravity And Into Space!

Did you know that steel can be used to make a spacecraft? You might think that this is obvious because spacecraft are large and heavy too! But if steel was just a heavy material, could it be used in building spaceships that have to go up high in the sky?

The material for a spaceship’s body must be as light as possible because the heavier the aircraft becomes, the more fuel it will consume, and the slower it would fly — due to gravity. However, light materials like plastic can’t be used as well since they aren’t durable. So special alloy materials such as duralumin are mainly used in making spaceships.

▲ If you want to see the stainless steel spacecraft from rocket maker SpaceX, click here!

January 2019, Elon Musk, the CEO of Tesla, announced that he would build ‘Starship’ out of stainless steel. Elon Musk is the founder of SpaceX, a rocket & spacecraft manufacturer. SpaceX is working on the development of a starship that can transport people from Earth to space — specifically to Mars.

Originally, the starship was to be made of carbon fiber, which is both light and durable. However, the material was changed to stainless steel since it was cheaper — one-hundredth the cost of carbon fiber — and could better withstand high temperatures with a melting point of 1,538 ℃. The starship will be 50 meters long and nine meters in diameter. Steel isn’t just for structures on the ground, but suitable for space adventures as well. Isn’t it amazing?

l In Your Pockets Today

You might have read about it in the papers, but there is steel in our smartphones as well. The silver rim of the Apple iPhone X is POSCO’s stainless steel.

▲ The shiny silver rim of iPhone X! It’s made of POSCO’s stainless steel!

The POSCO product used here is ‘non-magnetic, ultra-clean stainless steel.’ It has quite a long name, but you can easily get the idea of the product from it. The steel used for phones should be non-magnetic since it shouldn’t interfere with the phone connection. Additionally, the surface of the product must be ultra-clean — without scratches, bubbles, or deformations. That’s why ‘non-magnetic, ultra-clean stainless steel’ is the perfect material for smartphones!

Steel that fits a smartphone — the size of a palm and weighing only 174g — is the same stainless steel used for spaceships. But much thinner and lighter. The sleek and ‘edgy’ design that the steel rim provides is an additional feature. It shows a glimpse of what steel can do!

The answer to the question of whether POSCO makes only large and heavy steel is ‘Half correct and half wrong.’ Like mentioned above, steel could be used on a giant spaceship, and also on a hand-sized cell phone. Whether it’s steel used for aircraft or steel used for mobile phones, they all start with the same molten iron, but the applied technology is diverse — From needle to aerospace. Don’t you think this is the real strength of steel and POSCO? ⌯’▾’⌯