Answer:
The answer is below
Step-by-step explanation:
Case hardening is a form of steel hardening that is applied on mild steel with a high temperature of heat.
It results in material forming a hard surface membrane, while the inner layer is soft.
It is mostly used for universal joints, construction cranes, machine tools, etc.
On the other hand, Through hardening is a form of steel hardening in engineering that involves heat treatment of carbon steel.
It increases the hardness and brittleness of the material.
It is often used for axles, blades, nuts and bolts, nails, etc.