ln selecting a ductile cast iron for a high strengthlow duct

ln selecting a ductile cast iron for a high strength/low ductility application you find the following two tables in a standard reference. If specifications require a tensile strength ~ 550 MPa and a % elongation at fracture ~ 5%, which of these alloys would be suitable?

Tensile Strength of Ductile Irons Grade or Class UTS, MPa Class B 65-45-12 80-55-06 100-70-03 120-90-02 % Elongation of Ductile Irons Grade or Class % Elon Class B 65-45-12 80-55-06 100-70-03 120-90-02 12 6 379 448 552 689 827 2

Solution

Class 80-55-06 is selected since it meets all the requirement I.e tensile strength 552Mpa and %elongation 6