Mild Steel is not hard and brittle. Once Mild Steel is subjected to heating and then allowed to cool, it forms different compounds of steel having different properties.
This depends upon
1. The heating temperature
2. The time allowed for cooling.
When MS is heated to high temperatures so that it appears red hot and then suddenly cooled down to ambient temperature, it forms a compound called Martensite, which is hard. This is because there is more carbon in Martensite then in Mild Steel. This process of altering properties of compounds by heat is called heat treatment.
mild steel
heated up to kindling temperature of the mild steel
yes of course
heating mild steel to 200c
contracts (get smaller)
The main difference between cast iron and mild steel is the carbon content. Mild steel has a lower carbon content than cast iron. This makes cast iron brittle, while mild steel is much harder.
contracts (get smaller)
Specifics of their alloys, they'll have different proportions of carbon, iron, chrome etc. These changes will make the one known as steel a little stronger and harder to machine than the one called mild steel.
mild steel is heavier
One can describe the process of case hardening of mild steel by adding carbon particles while tempering the steel. The outside of steel will become hard which form the case and inside the metal, it remains soft.
Mild steel
Mild steel, not copper.