MMET 207 FINAL QUESTIONS AND ANSWERS
Ch. 2 Engineering Materials and Properties
Mechanical Properties of Steel - Answers :Strength, Formability, Stiffness, Toughness,
Durability
Types of Strengths - Answers :tensile Strength, yield strength, compression, flexural,
shear, creep, stress rupture
Types of Formability - Answers :percent elongation, percent reduction in area, bend
radius
Types of Stiffness - Answers :modulus of elasticity, flexural modulus, shear modulus
Types of Toughness - Answers :impact strength, notch strength, critical stress factor
Types of Durability - Answers :hardness, wear resistance, fatigue strength
Stress - Answers :F/A
units = lb/in^2
Strain - Answers :(Lf - Lo) / (Lo)
units = in/in
Modulus of Elasticity - Answers :(change in stress) / (change in strain)
Proportional Limit - Answers :where the linear relationship ends
Elastic Limit - Answers :point at which a metal can't return to elastic behavior
Percent Elongation - Answers :(Lf - Lo) / (Lo) x 100
1/16" Tungsten Ball - Answers :Rockwell B, T
120 Diamond Brale - Answers :Rockwell A, C, N
Superficial Loads - Answers :3 kg ... 15 kg, 30 kg, 45 kg
Regular Loads - Answers :10 kg ... 60 kg, 100 kg, 150 kg
Rockwell A loads - Answers :10 kg; 60 kg; diamond
, Rockwell C loads - Answers :10 kg; 150 kg; diamond
Impact Methods - Answers :charpy, izod, drop - weight
DBTT - Answers :Ductile to Brittle Transition Temperature
impact strengths vary at different tempratures
Fatigue Testing - Answers :repeatedly loading a specimen till its breaking point; metal
remembers each load
Endurance Limit - Answers :the point at which a metal can take infinite loads w/out
breaking
Creep Testing - Answers :used when metals are heated up to high temperatures over
time
Creep curve... describe sections A, B, C, & D - Answers :A = elastic strain
B = creep @ decreasing rate
C = creep @ steady state
D = creep @ increasing rate
Ch. 12 Steel Products - Answers :........
Blast Furnace - Answers :1st step in steelmaking process
Blast Furnace Charge - Answers :charged with iron ore, limestone, and coke; limestone
acts as a flux
Blast Furnace Steps - Answers :1) heat melts iron
2) limestone forms slag
3) remove and repeat
4) liquid iron poured into molds
Result of Blast Furnace? - Answers :iron ore => pig iron (3% - 5%)
Gas Reduction Chemical Formulas - Answers :1) C (coke) + O2 (air) ---> CO2
2) CO2 + C (excess coke) ---> 2CO
Iron Oxide Reduction Chemical Formulas - Answers :1) 2Fe2O3 (ore) + 3C (coke) --->
4Fe + 3CO2
2) Fe2O3 (ore) + 3CO ---> 2Fe + 3CO2
Ch. 2 Engineering Materials and Properties
Mechanical Properties of Steel - Answers :Strength, Formability, Stiffness, Toughness,
Durability
Types of Strengths - Answers :tensile Strength, yield strength, compression, flexural,
shear, creep, stress rupture
Types of Formability - Answers :percent elongation, percent reduction in area, bend
radius
Types of Stiffness - Answers :modulus of elasticity, flexural modulus, shear modulus
Types of Toughness - Answers :impact strength, notch strength, critical stress factor
Types of Durability - Answers :hardness, wear resistance, fatigue strength
Stress - Answers :F/A
units = lb/in^2
Strain - Answers :(Lf - Lo) / (Lo)
units = in/in
Modulus of Elasticity - Answers :(change in stress) / (change in strain)
Proportional Limit - Answers :where the linear relationship ends
Elastic Limit - Answers :point at which a metal can't return to elastic behavior
Percent Elongation - Answers :(Lf - Lo) / (Lo) x 100
1/16" Tungsten Ball - Answers :Rockwell B, T
120 Diamond Brale - Answers :Rockwell A, C, N
Superficial Loads - Answers :3 kg ... 15 kg, 30 kg, 45 kg
Regular Loads - Answers :10 kg ... 60 kg, 100 kg, 150 kg
Rockwell A loads - Answers :10 kg; 60 kg; diamond
, Rockwell C loads - Answers :10 kg; 150 kg; diamond
Impact Methods - Answers :charpy, izod, drop - weight
DBTT - Answers :Ductile to Brittle Transition Temperature
impact strengths vary at different tempratures
Fatigue Testing - Answers :repeatedly loading a specimen till its breaking point; metal
remembers each load
Endurance Limit - Answers :the point at which a metal can take infinite loads w/out
breaking
Creep Testing - Answers :used when metals are heated up to high temperatures over
time
Creep curve... describe sections A, B, C, & D - Answers :A = elastic strain
B = creep @ decreasing rate
C = creep @ steady state
D = creep @ increasing rate
Ch. 12 Steel Products - Answers :........
Blast Furnace - Answers :1st step in steelmaking process
Blast Furnace Charge - Answers :charged with iron ore, limestone, and coke; limestone
acts as a flux
Blast Furnace Steps - Answers :1) heat melts iron
2) limestone forms slag
3) remove and repeat
4) liquid iron poured into molds
Result of Blast Furnace? - Answers :iron ore => pig iron (3% - 5%)
Gas Reduction Chemical Formulas - Answers :1) C (coke) + O2 (air) ---> CO2
2) CO2 + C (excess coke) ---> 2CO
Iron Oxide Reduction Chemical Formulas - Answers :1) 2Fe2O3 (ore) + 3C (coke) --->
4Fe + 3CO2
2) Fe2O3 (ore) + 3CO ---> 2Fe + 3CO2
