1. Effect of carbon percentage
- Based on carbon percentage, material is classified broadly into steels and cast iron.
- Generally, Cast Iron has a carbon percentage of above 2.11% while less than that is considered as steels.
- Higher carbon percentage means more brittle material and hence less ductile material.
- Hence, for lower carbon material there is high toughness which means it has better ability to store impact energy and high carbon percentage material will have lower toughness and hence less ability to store impact energy.
2. Effect of heat treatment and grain size
- Faster cooling results in smaller grains and hence higher hardness in material. This results in lower ability of the material to store impact energy.
- Slower cooling allower the material to have comparatively bigger grain size. This results in material having more toughness hence the ability to store impact energy is more.
3. Effect of prior history of plastic deformation
- If the material has not been plastically deformed before, it has more ability to store any impact energy.
- While a material having prior history of plastic deformation has compaartively less toughness hence it has less ability to store any impact energy.
4. Effect of temperature
- The strength of steel increases upto 200-300 ∘C while post that the creep effect becomes dominant and hence its strength reduces.
- The effect of temperature on stress strain curve and hence its toughness is illustrated in the below figure.