EGR 250 Exam 1 | 100% Verified Questions and
Answers Rated A+ | 2026\2027 Latest Edition
Type A graphite flakes
-Correct Answer-uniformly distributed and randomly oriented
Type B graphite flakes
-Correct Answer-clusters or rosettes
Type C graphite flakes
-Correct Answer-thick, coarse flakes (kish), hypereutectic
Type D graphite flakes
-Correct Answer-small, randomly oriented interdendritic flakes
type E graphite flakes
-Correct Answer-interdendritic, preferred orientation
Forms of Graphite
-Correct Answer-
I - VII
I = spheroidal
VII = thin flake
Size of Graphite
-Correct Answer-
sizes 1-8
1=largest (128mm)
8 = smallest(1mm)
Mechanical properties of gray cast iron
-Correct Answer-good machinability
excellent damping capacity
better temperature resistance than steels
Physical Properties of gray cast iron
-Correct Answer-
- density - composition and temperature dependent
- Thermal conductivity - more free graphite = increased thermal conductivity
, - Electrical resistivity - more graphite = increased electrical resistivity
- thermal exapnsion
applications of gray cast irons
-Correct Answer-machine bases and supports, engine cylinder blocks, brake
components
Damping capacity
-Correct Answer-The ability of a material to absorb vibrations.
Spheroidal Graphite cast iron other names
-Correct Answer-nodular, spherulitic, ductile
Spheroidal cast iron production steps
-Correct Answer-Desulfurization, nodularization, inoculation
Desulfurization
-Correct Answer-melting low sulfur iron, mixing in the FE and desulfurizing agent
(usually CaC2)
- sulfur causes graphite to form as flakes instead of nodules (nullifies the effects of Mg
added)
Nodularization
-Correct Answer-addition of Mg to cause graphite to precipitate as spheres rather than
flakes
Mg to be added equation
-Correct Answer-wt.%Mg to be added = (0.75(initial wt.%S)+ (Residual wt.%Mg))/
(expected wt.% Mg recovery)
Inoculation
-Correct Answer-addition of an agent such as FeSi, that provides nucleation sites at
which graphite precipitates during solidification
- without it, Mg will cause white cast iron formation
Applications of Wrought iron
-Correct Answer-
- chains
- anchors
- railway coupling
Answers Rated A+ | 2026\2027 Latest Edition
Type A graphite flakes
-Correct Answer-uniformly distributed and randomly oriented
Type B graphite flakes
-Correct Answer-clusters or rosettes
Type C graphite flakes
-Correct Answer-thick, coarse flakes (kish), hypereutectic
Type D graphite flakes
-Correct Answer-small, randomly oriented interdendritic flakes
type E graphite flakes
-Correct Answer-interdendritic, preferred orientation
Forms of Graphite
-Correct Answer-
I - VII
I = spheroidal
VII = thin flake
Size of Graphite
-Correct Answer-
sizes 1-8
1=largest (128mm)
8 = smallest(1mm)
Mechanical properties of gray cast iron
-Correct Answer-good machinability
excellent damping capacity
better temperature resistance than steels
Physical Properties of gray cast iron
-Correct Answer-
- density - composition and temperature dependent
- Thermal conductivity - more free graphite = increased thermal conductivity
, - Electrical resistivity - more graphite = increased electrical resistivity
- thermal exapnsion
applications of gray cast irons
-Correct Answer-machine bases and supports, engine cylinder blocks, brake
components
Damping capacity
-Correct Answer-The ability of a material to absorb vibrations.
Spheroidal Graphite cast iron other names
-Correct Answer-nodular, spherulitic, ductile
Spheroidal cast iron production steps
-Correct Answer-Desulfurization, nodularization, inoculation
Desulfurization
-Correct Answer-melting low sulfur iron, mixing in the FE and desulfurizing agent
(usually CaC2)
- sulfur causes graphite to form as flakes instead of nodules (nullifies the effects of Mg
added)
Nodularization
-Correct Answer-addition of Mg to cause graphite to precipitate as spheres rather than
flakes
Mg to be added equation
-Correct Answer-wt.%Mg to be added = (0.75(initial wt.%S)+ (Residual wt.%Mg))/
(expected wt.% Mg recovery)
Inoculation
-Correct Answer-addition of an agent such as FeSi, that provides nucleation sites at
which graphite precipitates during solidification
- without it, Mg will cause white cast iron formation
Applications of Wrought iron
-Correct Answer-
- chains
- anchors
- railway coupling
