MMET 207 Final Exam Questions with
Complete Solutions
Bainite is a mixture of needles of carbide and austenite. - Answer-False
The hardness of martensite goes down gradually during tempering at room temperature
subsequent to quenching. - Answer-False
Higher the tempering temperature, smaller is the tempering time needed. - Answer-True
Banite is tougher and harder than pearlite. - Answer-True
Tempering increases the hardness of quenched steels. - Answer-False
Steel refining means making steel from pig iron, scrap, or ore. - Answer-True
The source of heat in the electric arc furnace is an arc that is established between the
melt and graphite electrodes. - Answer-True
Electric arc furnaces can not be shut down between uses. - Answer-False
Segregation can be minimized by adding elements to the steel, such as aluminum and
chromium. - Answer-False
Hot-finished steels have lower mechanical properties than cold-finished steels. -
Answer-True
One of the two primary steel making processes is - Answer-EAF - electric arc furnace
In hot finishing, ingots are rolled to smaller shapes such as - Answer-Billets
Ferrite consists of FCC iron structure with carbon in solid solution - Answer-False
Longer tempering times are needed at higher temperatures then at lower temperatures.
- Answer-False
Both Ms and Mf temperatures decrease with increasing carbon content in steels. -
Answer-True
The grain size in austempered steels is coarse because of rapid grain growth. - Answer-
False
Bainite is harder than pearlite. - Answer-True
, More martensite is formed during subsequent cooling after quenching to room
temperature if room temperature is between Ms and Mf temperature. - Answer-True
Martensite is hard and tough. - Answer-False
In all heat treatment of steel the transformation of austenite is important. - Answer-True
Quench cracks are due to retained austenite in steels changing over to bainite. -
Answer-False
To form martensite, the critical cooling rate should be exceeded when the steel is
cooled. - Answer-True
Tempering is done in the tempering range 700-1200 degrees. - Answer-False
Hardenable steels are excellent for welding purposes because they have high
resistance to cracking. - Answer-False
Adding Nickel as an alloying element will increase toughness. - Answer-True
Adding Silicon as an alloying element will increase - Answer-Hardenability
Martensitic stainless steels are hardenable by heat treatment. - Answer-True
Ferritic stainless steels are hardenable by cold working. - Answer-False
Austenitic Stainless Steels have excellent weldability by almost all welding processes. -
Answer-True
Stainless steels are prone to crevice corrosion. - Answer-False
Stainless steels do not perform best in oxidizing environments. - Answer-False
The prefix, E, signifies a steel that is - Answer-made in the electric arc furnace
Which of the following is a physical property?
a. color
b. hardness
c. microstructure
d.valence
e. electronegativity
f. composition - Answer-Color
hardness = mechanical property
microstructure = chemical property
valence = chemistry term
electronegativity = chemical property
Complete Solutions
Bainite is a mixture of needles of carbide and austenite. - Answer-False
The hardness of martensite goes down gradually during tempering at room temperature
subsequent to quenching. - Answer-False
Higher the tempering temperature, smaller is the tempering time needed. - Answer-True
Banite is tougher and harder than pearlite. - Answer-True
Tempering increases the hardness of quenched steels. - Answer-False
Steel refining means making steel from pig iron, scrap, or ore. - Answer-True
The source of heat in the electric arc furnace is an arc that is established between the
melt and graphite electrodes. - Answer-True
Electric arc furnaces can not be shut down between uses. - Answer-False
Segregation can be minimized by adding elements to the steel, such as aluminum and
chromium. - Answer-False
Hot-finished steels have lower mechanical properties than cold-finished steels. -
Answer-True
One of the two primary steel making processes is - Answer-EAF - electric arc furnace
In hot finishing, ingots are rolled to smaller shapes such as - Answer-Billets
Ferrite consists of FCC iron structure with carbon in solid solution - Answer-False
Longer tempering times are needed at higher temperatures then at lower temperatures.
- Answer-False
Both Ms and Mf temperatures decrease with increasing carbon content in steels. -
Answer-True
The grain size in austempered steels is coarse because of rapid grain growth. - Answer-
False
Bainite is harder than pearlite. - Answer-True
, More martensite is formed during subsequent cooling after quenching to room
temperature if room temperature is between Ms and Mf temperature. - Answer-True
Martensite is hard and tough. - Answer-False
In all heat treatment of steel the transformation of austenite is important. - Answer-True
Quench cracks are due to retained austenite in steels changing over to bainite. -
Answer-False
To form martensite, the critical cooling rate should be exceeded when the steel is
cooled. - Answer-True
Tempering is done in the tempering range 700-1200 degrees. - Answer-False
Hardenable steels are excellent for welding purposes because they have high
resistance to cracking. - Answer-False
Adding Nickel as an alloying element will increase toughness. - Answer-True
Adding Silicon as an alloying element will increase - Answer-Hardenability
Martensitic stainless steels are hardenable by heat treatment. - Answer-True
Ferritic stainless steels are hardenable by cold working. - Answer-False
Austenitic Stainless Steels have excellent weldability by almost all welding processes. -
Answer-True
Stainless steels are prone to crevice corrosion. - Answer-False
Stainless steels do not perform best in oxidizing environments. - Answer-False
The prefix, E, signifies a steel that is - Answer-made in the electric arc furnace
Which of the following is a physical property?
a. color
b. hardness
c. microstructure
d.valence
e. electronegativity
f. composition - Answer-Color
hardness = mechanical property
microstructure = chemical property
valence = chemistry term
electronegativity = chemical property
