Okay kiddo, imagine you have a metal toy car that you want to make even stronger and better looking. Well, one way to do that is called electro-slag remelting.
First, you stack a bunch of metal pieces on top of each other and put them in a special container called an electrode. Then, you melt the metal by heating it up with electricity, like when you turn on a light switch.
Next, you add some special material called flux to the metal. Think of it like putting icing on a cake - it helps make the metal smoother and gets rid of any impurities that might be left in there.
As the metal melts and mixes with the flux, it starts to form a pool at the bottom of the electrode. This pool turns into a new piece of metal that is stronger and more pure than the original metal pieces.
It might take some time, but eventually, you have a brand new piece of metal that is remelted and remade to be stronger and better looking than before. And that's what electro-slag remelting is!