Once you have added the carbon to the iron to make stee […]
Once you have added the carbon to the iron to make steel, adding chromium to the mix creates what we know as stainless steel. It is even tougher than the parent element iron. That is why construction now uses more steel than iron.The percentage of carbon makes yet another difference. Iron that has less than 2% carbon is called steel and if the carbon content is more tan this 2% it is called pig iron.
To make pig iron the ore is combined with coke in a blast furnace.A lot of people have confused steel and iron over the years. The main difference is that iron is an element of which steel is an alloy. It is sort of like a parent and child relationship. First was the iron and by adding carbon to the iron you get steel. You see how that works. The steel has the properties of both. Like a child has a trait from both mother and father.
You can even add to steel other metals that change its properties into something else entirely. Then the pig iron is processed to reduce the amount of carbon to make it into steel. Once the steel is made other alloys such as manganese, silicon and chromium is added to make other different alloys. No one is certain how the first iron was formed from the ore.
But archaeologists have found samples of iron in Egypt that date to 3000BC, and in Greece back to 1000BC. This type of hardened iron was used to make weapons. In the 14th century furnaces got larger and the process of blasting the smelted ore with rich carbon gases produced the first pig iron. Before then it was all wrought iron. Experimentation and further processing eventually yielded the steel, as we know it today.
|cobalt chromium alloy|