Chapter Five Exam

Question 1

The melting temperature of aluminum is

Answer 1

660.

Question 2

There are several approaches to the rolling of steel plate, which of the following is correct? (Multiple Choice)

Answer 2

Hot rolling is carried out in the austenite region.

Question 3

The first step in converting iron ore into steel is the production of pig iron in the:

Answer 3

Blast furnace.

Question 4

Molten steel contains dissolved oxygen, which tends to make steel brittle. An alloying element that can be added to reduce the amount of oxygen is:

Answer 4

Aluminum.

Question 5

During the smelting of iron, “reduction” refers to removing:

Answer 5

Carbon? NO.

Question 6

The carbon content of a specific steel grade, e.g. 4340:

Answer 6

Not be uniformed but in a specified range.

Question 7

What is a prime requirement when purchasing steel?

Answer 7

Steel specifications.

Question 8

What is the best way to explain slip during plastic deformation?

Answer 8

Through dislocations.

Question 9

Grain size can influence the properties of steel in significant ways. What heat treatment is selected to improve the toughness of steel?

Answer 9

Normalizing reduces grain size to increase toughness.

Question 10

Steel between 0.8% and 1.7% carbon at room temperature will exhibit a microstructure of:

Answer 10

Pearlite and cementite.

Question 11

When a pressure vessel is made from formed plates, they are usually arranged?

Answer 11

Rolling direction around the circumference.

Question 12

There are many other ways in which a steel may be strengthened. Which of the following is a correct approach? (Multiple Choice)

Answer 12

Impede the passage of dislocations by alloying.

Question 13

Why are silicon and/or aluminum added to steel?

Answer 13

Added to remove dissolved oxygen.

Question 14

A crystal that has an edge dislocation means:

Answer 14

None of above? No.

Question 15

What is the maximum solubility of carbon in austenite and above which a steel becomes cast iron?

Answer 15

Max solubility of carbon in austenite is 1.7%.

Question 16

The ductility measured through the thickness of the plate is usually the lowest of all. The welding of large heavily restraint tee joints may therefore result in

Answer 16

Lamellar tearing.

Question 17

In the precipitation hardening alloys, change in hardness during aging can be influenced by: (Multiple Choice)

Answer 17

Temperature and time.

Question 18

There are several steel types, one is the TMCP type steels. What are these?

Answer 18

Controlled hot working and micro alloyed steel composition.

Question 19

Why can the properties of steel be changed through heat treatment?

Answer 19

Steel expands as it heats up? NO.Because of the phase changes from BCC to FCC to BCC??

Question 20

Hammering a copper bar several times at room temperature causes:

Answer 20

Dislocation and work hardening.

Question 21

The process whereby steel is heat treated to a point where the structure transforms and new grains grow is referred to as:

Answer 21

Recrystallization.

Question 22

Metals have a crystalline structure in which atoms are arranged in irregular patterns.

Answer 22

False.

Question 23

A piano wire of 0.8% of carbon has a tensile strength of 435 ksi ( 3000 MPa), because of: (Multiple Choice)

Answer 23

Work hardening.

Question 24

The blast furnace is used to extract the iron from its oxide, what is the product of the blast furnace? (Multiple Choice)

Answer 24

Pig iron that contains impurities such as phosphorus and about 3% or 4% carbon.

Question 25

When fabricating a high strength quenched and tempered steel, what post weld requirement will need effective control?

Answer 25

Post weld heat treatment must ensure the temperature does not exceed the tempering temperature otherwise it may have significant drops in strength.

Question 26

What is the effect of a small grain size in steels?

Answer 26

Increases toughness and tensile strength.

Question 27

If more than 0.8% carbon is added to iron

Answer 27

Result will contain cementite and pearlite.

Question 28

There are several metallurgical phases in a steel depending on its carbon content and heating history. How is ferrite best described? (Multiple Choice)

Answer 28

Solid solution in BCC phase of iron that dissolves very small amounts of carbon.

Question 29

What kind of furnaces dominate steelmaking in the today's world?

Answer 29

Basic oxygen and electric furnaces.

Question 30

When designing a steel to improve its hardenability and thus its strength, what is the normal approach?

Answer 30

Use small amounts of several hardening elements as the effect is better than a single element.

Question 31

Which of the following steels will require the most stringent control of the welding procedure?

Answer 31

700Q.

Question 32

What is the difference between Eutectic point and Eutectoid point?

Answer 32

Eutectic, liquid in the phase diagram forms two solids. Eutectoid is a single solid in the phase diagram forms two solids.

Question 33

Killed steels are?

Answer 33

Fully deoxidized.

Question 34

Hot shortness is:

Answer 34

Cracking susceptibility due to high Sulphur content.

Question 35

The formation of a martensitic structure can be assisted by which of the following techniques

Answer 35

Adding alloying elements to steel such as chromium.

Question 36

Alloys are mixtures of a metal with

Answer 36

Both metals and non metals.

Question 37

The three basic steps in precipitation hardening are solution treatment, quenching and:

Answer 37

Aging.

Question 38

Increases in carbon content can affect the properties of steel in which of the following areas?

Answer 38

Tensile strength increases but ductility and weldabiliy decrease.

Question 39

The carbon content for quenched and tempered steels used for earth moving and mining equipment will be:

Answer 39

0.2% Max.

Question 40

How is the yield point phenomenon explained?

Answer 40

Dislocations are pinned by interstitial atoms.

Question 41

Thicker plates of the same steel designation will be designed with higher

Answer 41

Carbon content.

Question 42

When making steel, the first process is to convert iron ore into pig iron. Which furnace is used for this process?

Answer 42

Blast.

Question 43

What is pearlite?

Answer 43

A layered form of ferrite and cementite.

Question 44

During rolling of a steel plate, non-metallic inclusions in the steel plate may produce:

Answer 44

Elongated inclusions.

Question 45

Grain boundaries are the regions where atoms are in perfect order

Answer 45

False.

Question 46

High carbon steels typically provide:

Answer 46

High strength.

Question 47

Why is sulphur added to structural steels?

Answer 47

It is not added. It is an impurity.

Question 48

Which one of the following elements influences the shifting of lines in the phase diagram of steel to a point where steel becomes 100% austenite?

Answer 48

Nickel.

Question 49

How can low sulphur steels be produced if desired to give improved through-thickness properties?

Answer 49

By using additives such as calcium.