a$)$ requires an accurate listing of properties required and a detailed $($at least $4$ per cast iron$)$ description of the

properties of each type of cast iron including why they have these properties and a comparison with other types of cast iron;

$($b$)$ This is essentially marked as correct or incorrect;

$($c$)$ Equal marks are given to each temperature and full marks requires a correct listing of the phases, their proportions and a labelled sketch.