Chapter 8 practice test. Flashcards
As a metal is heated:
a. energy is added to the structure
b. the atoms move further apart
c. the atoms vibrate more vigorously
d. the metal expands
e. all of the above
e. all of the above
The state of matter which exhibits the least amount of energy is:
a. solid
b. liquid
c. gas
d. quasi-liquid
e. none of the above
a. solid
Q 8-3 A problem occurring in weldrnents caused by the nonuniform heating produced by the welding operation is: a. porosity b. incomplete fusion c. distortion d. slag inclusions e. none of the above
c. distortion
Which of the following is not a method used to eliminate or reduce residual stresses?
a. vibratory stress relief
b. external restraint ‘
c. thermal stress relief
d. peening
e. annealing
b. external restraint
The type of alloying in which the alloy atoms are located in the spaces between the atoms of the parent metal is referred to as: a. atomic alloying b. substitutional alloying c. space alloying d. interstitial alloying e. none of the above
d. interstitial alloying
Rapid quenching of a steel from the austenitic range results in a hard, brittle structure known as: a. pearlite b. carbide c. cementite d. ironite e. martensite
e. martensite
Very slow cooling of steel may result in the production of a soft, ductile microstructure which as a lamellar appearance when viewed under high magnification. This structure is referred to as :
a. martensite
b. pearlite
c. bainite
d. femte
e. cementite
b. pearlite
When rapid cooling produces a martensitic structure, what sub-critical heat treatment may be applied to improve the ductility of the steel?
a. quenching
b. tempering
c. annealing
d. normalizing
e. none of the above
b. tempering
It is determined that a welding procedure is creating an excessive heat input. Which of the changes listed below would result in a reduction of the heat input?
a. decrease current
b. decrease voltage
c. increase travel speed
d. change from weave to stringer bead technique
e. all of the above
e. all of the above
The use of preheat will tend to:
a. result in a wider heat-affected zone
b. produce a lower heat-affected zone hardness
c. slow down the cooling rate
d. reduce the tendency to produce martensite in the heat-affected zone
e. all of the above
e. all of the above
Which of the following changes will warrant an addition or increase in the required preheat?
a. decreased carbon equivalent
b. increased carbon equivalent
c. increased base metal thickness
d. a and c above
e. b and c above
e. b and c above
What heat treatment is characterized by holding the part at the austenitizing temperature for
some time and then slow cooling in the furnace?
a. normalizing
b. quenching
c. annealing
d. tempering
e. stress relief
c. annealing
What heat treatment is characterized by holding the part at the austenitizing temperature for some time and then cooling in still air?
a. normalizing
b. quenching
c. annealing
d. tempering
e. stress relief
a. normalizing
Steel heated above the lower transformation temperature (Al,) will change microstructural
alignment. This temperature is?
a. 13330F
b. 9330 F
c. 15600F
d. 36000 C
e. none of. the above
a. 13330F
Atoms in the solid (frozen) state
a. have a specific “home” position
b. have no distinct structure
c. are essentially futed in a definite structured position
d. a and c above
e. none of the above
d. a and c above
What is the heat input for a molten weld pool at 5 ipm travel speed, 25 volts, and 100 amperes. (Refer to Formula) a. 300 J/in. b. 300,000 J/in. c. 30,000 J/in. d. 3.633 J/in. e. none of the above
c. 30,000 Jlin
One way that atoms are added to a pure metal to form an alloy is:
a. peening
b. substitutionally
c. automatically
d. soli&fication
e. diffusion
b. substitutionally
The process where carbon is added to the surface of a steel to harden it is:
a. decarburization
b. pack carburizing
c. precipitation hardening
d. quenching
e. none of the above
b. pack carburizing
Steel exists in which of the following crystal structures?
a. BCT
b. FCC
c. BCC
d. all of the above
e. HCP
d. all of the above
Which of the following usually follows quenching?
a. tempering
b. stress relieving
c. normalizing
d. annealing
e. none of the above
a. tempering
Which of the following can be accomplished using either thermal or mechanical techniques?
a. annealing
b. tempering
c. quenching
d. stress relieving
e. none of the above
b. tempering
Which of the following results in the softest condition for carbon steel?
a. annealing
b. quenching
c. stress relieiving
d. tempering
e. normalizing
a. annealing
For a steel having a chemistry of: 0.16% carbon, 0.84% manganese, 0.09% nickel, 0.25%
\ chromium, 0.052% copper, and 0.40% molybdenum, what is its Carbon Equivalent?
.046
Stainless steels are defined as having at least what percent chromium?
12%
Sensitization, or carbide precipitation, of austenitic stainless steels can be reduced by which of the following methods?
a. solution annealing, water quenching
b. using stabilized grades containing titanium or niobium (columbium)
c. using the low carbon grades of stainless steels
d. all of the above
e. using high carbon stainless steels
d. all of the above
Metals must be molten for diffusion to occur.
a. true
b. false
b. false
Hydrogen can diffuse into a solid metal at room temperature.
a. true
b. false
a. true
Metals can dissolve into each other when both are in the solid form.
a. true
b. false
a. true
The process whereby nitrogen is dissolved into the surface of carbon steel is?
a. sensitization
b. nitrogen removal
c. carburizing
d. nitriding
e. none of the above
d. nitriding
Welding metallurgy is concerned with the changes in the metals during welding.
a. true
b. false
a. true
