Čelik je legura od željeza, ugljika i drugih elemenata. Čelik je jeftin za proizvodnju i ima veliku čvrstoću rastezljivosti. Čelik ima mnoge koristi, uključujući brodogradnju, gradnju i automobile.
Steel is a mixture of mostly iron and carbon, with varying amounts of other elements mixed in. After aluminium, iron is the second most abundant metal in the Earth’s crust. Pure iron can be quite soft and easily bent. In pure iron, the atoms easily slide past each other. The carbon acts as a hardening agent and it stops the iron atoms moving as easily. Steel can contain up to 2.1% carbon. If any more carbon is added, then the substance is known as cast iron.
Steel has been used extensively throughout history. The earliest known steel production came from Anatolia (modern day Turkey) in 1800 BCE. Steel was used for creating weapons, such as swords and spears, but also tools. Centuries later, the Bessemer process brought in a new era of steel making. The Bessemer process was patented in 1856 by the processes’ inventor, Henry Bessemer. This industrial process allowed for the mass production of steel from molten pig iron and greatly reduced the cost of steel production.
To create stainless steel, chromium is added to steel. A hard oxide forms on the surface, which stops corrosion. Stainless steel has many applications, including chemical tankers, cookware, and surgical instruments, as it can be steam cleaned and sterilized with a reduced risk of corrosion.
Steel has a wide range of applications and is commonly used in making buildings, ships, cars, machines, weapons, tools, and household appliances. Large buildings and structures, such as stadiums and airports, are often built with a steel skeleton. Steel is one of the world’s most recycled materials, with a global rate of 60%.
{Microdata type="HowTo" id="10078"}Čelik je legura uglavnom od željeza i malog udjela ugljika, što ga čini jačim i fleksibilnijim od čistog željeza. Za razliku od željeza, čelik otporan je na rđu i koristi se u mnogim građevinskim i proizvodnim primjenama.
Čelik se proizvodi topljenjem željeznih ruda i dodavanjem ugljiika te ponekad drugih elemenata. Ovaj proces uklanja nečistoće, što rezultira jačim i dugotrajnijim metalom koji se koristi u zgradama, vozilima i alatima.
Čelik je ključan jer se koristi za izradu automobila, mostova, kućanskih uređaja, pa čak i školskog pribora. Njegova snaga i fleksibilnost čine ga omiljenim materijalom za mnoge proizvode koje svakodnevno koristimo.
Čelik se često koristi u zgradama, mostovima, cijevima i armiranom betonu. Njegova sposobnost da podrži teška opterećenja i odolijeva vremenskim uvjetima čini ga idealnim za građevinske projekte.
Postoji nekoliko vrsta čelika, poput ugljeničnog čelika (za gradnju), nehrđajućeg čelika (za kuhinjski pribor) i zlitog čelika (za strojeve). Svaka vrsta ima jedinstvena svojstva za različite primjene.