Metallurgy

Question 1

What is the name given by scientists to a
substance made only of one type of atom?
a. Phase
b. Element
c. Ferrite
d. BCC

Answer 1

b. Element

Question 2

What is an alloy?
a. High strength low toughness steel
b. Formable grade of aluminum
c. A material composed of two or more
elements.
d. A mixture of ferrite and martensite

Answer 2

c. A material composed of two or more elements.

Question 3

What are the three states of matter?
a. Plasma, solid, gas
b. Solid, gas, liquid
c. Gas, liquid, solid
d. Ferrite, solid, liquid

Answer 3

b. Solid, gas, liquid

Question 4

Name the three most common steel numbering
systems;
a. CSA, TSSA, BCSA
b. CSA, ASTM, AISI
c. CSA, ASME, ABSA
d. CSA, ABSA, BCSA

Answer 4

b. CSA, ASTM, AISI

Candian Standards Association
American Society of Mechanical Engineers
American Iron and Steel Institute

Question 5

What is the main difference between steel and
cast iron?
a. Steel cannot be cast
b. Cast iron has more carbon
c. Cast iron is easily forged
d. Steel is lighter than cast iron

Answer 5

b. Cast iron has more carbon

Question 6

Which crystalline structure does iron adopt at room temperature?
a. FCC
b. BCC
c. HCP
d. BCT

Answer 6

b. BCC

Question 7

What do we see when we look at metals under a
microscope?
a. Bacteria
b. BCC crystals
c. Grains
d. Carbon

Answer 7

c. Grains

Question 8

If a low alloy steel is cooled rapidly to room
temperature from above 910 ·c;
a. The steel will be softened
b. The steel will becomes harder
c. The steel produce large grains
d. The steel will reject its alloys

Answer 8

b. The steel will becomes harder

Question 9

What is martensite?
a. A hard structure caused by fast cooling
b. A tough phase made by slow cooling
c. Another name for complex iron carbide
d. A phase created during stress relief

Answer 9

a. A hard structure caused by fast cooling

Question 10

What is a phase diagram?
a. A “road map” of what structures ideally
want to form
b. A series of hardness curves
c. A cooling rate chart
d. A heat treatment chart

Answer 10

a. A “road map” of what structures ideally want to form

Question 11

What is the melting point (temperature) of pure
iron?
a. 500 ·c
b. 723 ·c
c. 910 ·c
d. 1535 ·c

Answer 11

d. 1535 ·c

Question 12

Why do we temper a “quenched” steel?
a. To increase its’ strength
b. To anneal the structure
c. To increase it’s toughness
d. To remove distortion

Answer 12

C. To increase it’s toughness

Question 13

One number corresponds to one letter.
1. Fused zone
2. HAZ
3. Bonding zone
4. Zone not affected by heat

A. Surface near the fused zone
B. No chemical or physical modifications
C. Where there is grain growth
D. Where metal reached a liquid state

Answer 13

1-D, 2-C, 3-A, 4-B

Question 14

Which element in steel contributes substantially to hardenability?

Answer 14

Carbon. Next highest in hardenability is manganese.

Question 15

A fine grained steel such as used for pipelines has what benefit?
a. Low carbon and controlled alloying
make it strong and tough
b. Fast cooling when welding produces
brittle martensite
c. High carbon content make them easily
heat treated
d. Reduces ductility at lower operating
temperatures

Answer 15

a. Low carbon and controlled alloying
make it strong and tough

Question 16

Which is the hardest type of structure (phase)?
a. bainite
b. austenite
c. martensite
d. ferrite

Answer 16

c. martensite

Question 17

Join the terms in the column to letters
A - Physical property or B - Mechanical property

Thermal conductivity
Elongation
Density
Hardness
Elasticity

Answer 17

Elongation = B - Mechanical property ,
density= A - Physical property
hardness= B - Mechanical property
elasticity= B - Mechanical property
Thermal conductivity=A - Physical property

Question 18

What series of stainless steel can be hardened by
heat treatment?
a. Ferritic
b. Pearlitic
c. Martensitic
d. Austenitic

Answer 18

c. Martensitic

Question 19

Which of the following heat treatments produces
the softer metal?
a. quenching
b. tempering
c. normalizing
d. annealing
e. stress relief

Answer 19

d. annealing

Question 20

Why can’t you weld austenitic stainless steel with
mild steel filler rod?
a. Causes lack of fusion
b. It will form martensite
c. The steel will be sensitized
d. Produces excessive porosity

Answer 20

b. It will form martensite

Question 21

21. What is the main difficulty in welding martensitic
    stainless steels?
    a. Cluster porosity
    b. Internal undercut
    c. Hydrogen cracking
    d. Angular distortion

Answer 21

c. Hydrogen cracking

Question 22

When welding stainless steels the heat
affected zone can become sensitize What is
“sensitization”?
a. Excessive hardness
b. Loss of corrosion resistance
c. Martensitic nodules
d. Delayed hydrogen cracking

Answer 22

b. Loss of corrosion resistance

Question 23

What is the difference between 304 and 304L
grades of stainless?
a. 304L has a lower carbon content
b. 304 has a lower carbon content
c. 304 has a lower nickel content
d. 304L has a lower chromium content

Answer 23

a. 304L has a lower carbon content

Question 24

What are the four basic types of Stainless steel
a. Ferritic, martensitic, austenitic, duplex
b. Ferritic, pearlitic, martensitic, bainitic
c. Ferritic, martensitic, duplex, pearlitic
d. Ferritic, martensitic, bainitic, duplex

Answer 24

a. Ferritic, martensitic, austenitic, duplex

Question 25

What physical property affects the feeding ability
of aluminum GMAW electrodes?
a. Low stiffness (modulus of elasticity)
b. Low yield strength (yield point)
c. Low density (weight per volume)
d. Low elongation (ductility)

Answer 25

a. Low stiffness (modulus of elasticity)

Question 26

The ability to conduct heat (thermal conductivity)
is much different between aluminum alloys?
Which alloy conducts heat faster?
a. 6061
b. 5083

Answer 26

a. 6061

Question 27

What is the main cause of cracking in aluminum
welds?
a. Delayed hydrogen
b. Weld chemistry
c. High stresses
d. Excessive distortion

Answer 27

b. Weld chemistry

Question 28

Cast iron repair welds are prone to porosity
because;
a. Oils will soak into the fracture surfaces
b. The heat affected zone is very hard
c. Nickel easily absorbs oily vapours
d. Cast iron is naturally full of gas

Answer 28

a. Oils will soak into the fracture surfaces