Hi, guys have you ever wondered why stainless steel is shiney and silvery while Mild steel is Black while the basic element to both of the product is same iron.

In this video we are going to dive into the reason of why these metal have all these different qualities and how they are modified.
If you dont know about the different proporties of metal like thoughness, hardness, ductility ,stiffness and brittleness check out my video on the proporties of material.
Now in this video we will understand how these proporties are modified on top of some other proporties using alloying elements during the manufacturing stage of matel making.
In my this video you will understand the secondery process of making steel in which we add alloying element in the ladle furnace. All these alloying elements are directly responsible for the adjustment of the basic proporties of steel.
So lets dive into what elements affacts what proporty and why do we use it.
SO WE all know that main element is Iron. And pure iron is not that stong. So we add elements like carbon, sulpher, mengeneze,
Silicon, phosphoras, chromium , molybdenum , nikel and some more as per the need.
Now lets start with Carbon. Carbon is the most important element for strength and hardness. The more carbon you add the more tensile strength you will get in the steel. Also carbon is available in good quantities in nature. It is one of the cheapst way of increasing strength of the steel.
Now sulpher is normaly known as an impurities because it reduces ductility, thoughness and weldability. But sometime it is added to increase machinability of steel.
Chromium increases hardenability of steel.
Joined with carbon it creats carbides on the surface. Which is used in most of the tools.
When chromium is added with molybdenum and nikel it increases hardenability of steel. Nickel increases
Thoughness in the metal. This is where stainless steel is made. It creates a thin layer of chromium oxide on the outer surface and prevents corrosion of the steel from oxygen diffusion to the steel. And if a surface is sctatched oxygen will again create chromin oxide instead of reacting with iron. This is why knife, kitchen utensils and mainly surgical equipment are made out of stainless steel.


Now Silicon is used to remove oxygen from the steel during de oxygedyyzin process in ladle furnace. If you have oxygen in the steel it creates void and blow holes in the steel which can reduce the strength of the steel. Also having oxygen present in the steel will create rust in the steel and reduce the strength.
Vanadium is used to increase the hardness and thoughness of the steel.
Now there is an element called boRon. It is used to increase the hardenability but more importantly it increases the effacts of other alloying element.
Nitrogen is added with other elements as nitrides which increases hardness and tensile strength. But it reduces thoughness and ductility of the metal.

NOW OUT OF all these elements carbon is the most important element and I will make a separate video on that explains different steel type just based on the carbon content.