STEEL Talk presents to you interesting stories of Science, Technology, Energy, Environment, Life — and of course STEEL!
Such a cute question! A little child sent us this note after visiting Pohang Works the other day. So we’ve opened up a new corner, [STEEL Talk] to tackle some questions like this, one by one. So, let’s get started!
Put simply, the answer is “Yes!” This unbelievably strong material is POSCO’s GIGA STEEL. First, let’s take a look at the image below and see how GIGA STEEL got its name and how strong it is.
Have you ever heard of the word “Giga”?
We use the word ‘Gigabyte’ when mentioning the capacity unit of a mobile phone or a computer. When you multiply 1,000 and Kilo — which means 1,000 — you get Mega. If you multiply that Mega by another 1,000, you get Giga. So you have to multiply 1,000 twice to get a Giga. That’s how big ‘Giga’ is.
Since GIGA STEEL has ‘Giga’ in its name, you can guess how strong this steel really is. Then how is it made? This has to do with the “rolling process”. When molten iron begins to solidify, many crystals appear and the shape of these crystals decides the property of the iron. So, if force is exerted on the iron and its crystal becomes even, the iron gets stronger. That is why the steelworks use big rollers to flatten out the iron evenly. This is called the rolling process.
GIGA STEEL also goes through this process. After adding a secret alloy to the molten iron from the furnace, and repeating the heating and rolling process, this super-strong steel is produced. Further details — what elements are added, how many times the heating and rolling is repeated — are POSCO’s secret, but you can get the idea, right?
We use the term ‘tensile strength‘ to describe the strongness of steel. Tensile strength is the amount of force steel can withstand when it is pulled on both sides. GIGA STEEL has a maximum tensile strength of 1,000 Mega Pa. Meaning, GIGA STEEL is an ultra high strength steel of more than 1 Giga Pa. (1,000 Mega Pa = 1 Giga Pa, Pa stands for Pascal, a unit for measuring pressure)
This means GIGA STEEL can withstand more than 100 kg per 1㎟ area. The surface area of a 10 won coin is 254.34㎟, so a 10-won coin can hold 25 tons!
Then how heavy is 25 tons? One ton is 1,000kg so 25 tons is 25,000 kg. And 25 tons equal to 710 children — each weighing 35 kg. A 10 won coin-sized GIGA STEEL can support children of a whole school! Isn’t it amazing?
This super-strong GIGA STEEL serves in a variety of uses in automobiles. Actually, your car might be using GIGA STEEL too!