120102d Heat Treatment

Question 1

The extent of the change of the grain structure in the heat-affected zone depends upon:
a) the temperature to which the metal is subjected.
b) the composition of the steel.
c) the rate of cooling.
d) all of the above.

Answer 1

d) all of the above.

Question 2

Which of the listed heat treatments alters the grain structure of the weld deposit and heat-affected zone?
a) stress relief
b) tempering
c) normalizing
d) preheating

Answer 2

c) normalizing

Question 3

Temperature refers to the:
a) intensity of heat.
b) amount of heat.
c) volume of heat.
d) quality of heat.

Answer 3

a) intensity of heat.

Question 4

The movement of heat within the body of a material is called:
a) radiation.
b) conduction.
c) convection.
d) transference.

Answer 4

b) conduction.

Question 5

The transfer of heat from one body to another is called:
a) radiation.
b) conduction.
c) convection.
d) transference.

Answer 5

c) convection.

Question 6

The movement of heat in air is called:
a) radiation.
b) conduction.
c) convection.
d) transference.

Answer 6

a) radiation.

Question 7

The rate of thermal conductivity refers to the:
a) melting temperature of a metal.
b) BTU output of an oxyfuel welding tip.
c) speed at which heat travels within a material.
d) time required to melt through the metal.

Answer 7

c) speed at which heat travels within a material.

Question 8

The material that requires the lowest heat input for welding because of its poor thermal conductivity is:
a) mild steel.
b) brass.
c) aluminum.
d) copper.

Answer 8

a) mild steel.

Question 9

The material that requires the greatest heat input for welding because of its high thermal conductivity is:
a) aluminum.
b) mild steel.
c) stainless steel.
d) cast iron.

Answer 9

a) aluminum.

Question 10

Restrained expansion of metal when it is heated results in:
a) internal cracking.
b) dimensional upset.
c) internal stress.
d) surface hardening.

Answer 10

b) dimensional upset.

Question 11

Unrestrained expansion and contraction of a metal when it is heated and allowed to cool slowly produces:
a) internal cracking.
b) dimensional upset.
c) no appreciable change.
d) surface hardening.

Answer 11

c) no appreciable change.

Question 12

The dimensional upset that occurs when expansion is restrained may be used to good advantage to:
a) remove broken studs.
b) use jigs and fixtures.
c) remove excess weld reinforcement.
d) weld around the neutral axis.

Answer 12

a) remove broken studs.

Question 13

What is the result of welding a section when both expansion and contraction are restrained?
a) excessive warping
b) loss of dimensions
c) very high stress
d) a good sound weld

Answer 13

c) very high stress

Question 14

On which of the following jobs would expansion and contraction work in your favour?
a) when welding a joint subject to a high degree of restraint
b) when repairing an exhaust manifold
c) when repairing the spoke on a flywheel
d) when welding aluminum tire rims

Answer 14

c) when repairing the spoke on a flywheel

Question 15

15. Preheating heavy sections can help:
    a) prevent weld bead cracking.
    b) increase internal stress.
    c) increase tensile strength.
    d) produce a fine grain structure.

Answer 15

a) prevent weld bead cracking.

Question 16

Metals that are to be welded and that are low in ductility are usually preheated in order to:
a) promote fine grain size.
b) slow the quench rate.
c) improve the hardenability.
d) increase welding stresses.

Answer 16

b) slow the quench rate.

Question 17

Which of the following cannot be accomplished with a postweld heat treatment?
a) annealing
b) normalizing
c) stress relieving
d) distortion control

Answer 17

d) distortion control

Question 18

What is the soaking time required to stress relieve a steel weldment that is one inch thick?
a) 1 hour
b) 2 hours
c) 3 hours
d) 4 hours

Answer 18

a) 1 hour

Question 19

The annealing of a steel fabrication should:
a) decrease distortion.
b) increase hardness.
c) decrease ductility.
d) decrease tensile strength.

Answer 19

d) decrease tensile strength.

Question 20

What effect does preheating have on a steel weldment?
a) It increases tensile strength and ductility.
b) It decreases tensile strength and ductility.
c) It increases tensile strength and decreases ductility.
d) It decreases tensile strength and increases ductility.

Answer 20

d) It decreases tensile strength and increases ductility.

Question 21

The heat-treating process that brings a material to its softest, toughest, weakest state is:
a) annealing.
b) normalizing.
c) stress relieving.
d) tempering.

Answer 21

a) annealing.

Question 22

Heating steel above its upper critical temperature and cooling in still air describes a heat treatment known as:
a) annealing.
b) normalizing.
e) stress relieving.
d) tempering.

Answer 22

b) normalizing.

Question 23

The temperature range lor stress relieving is:
a) 870°C (1600°F) to 980”(1800°F).
b) 760°C (I400°F) to 870°C (1600°F).
c) 595°C (1100°F) to 700°C (1300°F).
d) 425°C (800°F) to 535°C (1000°F).

Answer 23

c) 595°C (1100°F) to 700°C (1300°F).

Question 24

Tempering is a _____________ process.
a) case-hardening
b) preheating
c) hardening
d) toughening

Answer 24

d) toughening

Question 25

To produce grain structure uniformity throughout the weldment and critical areas, you would:
a) temper.
b) stress relieve.
c) normalize.
d) preheat.

Answer 25

c) normalize.

Question 26

Heating above the upper critical temperature followed by a rapid quench describes:
a) stress relieving.
b) normalizing.
c) tempering.
d) hardening.

Answer 26

d) hardening.

Question 27

Heating below the lower critical temperature followed by a rapid quench describes:
a) stress relieving.
b) normalizing.
c) tempering.
d) annealing.

Answer 27

c) tempering.

Question 28

A temperature-indicating crayon marked at 150°C (300°F) is used for:
a) hardening.
b) preheating.
c) stress relieving.
d) annealing.

Answer 28

b) preheating.

Question 29

Which of the following is a temperature-sensing device?
a) thermograph
b) inclinometer
c) barometer
d) pyrometer

Answer 29

d) pyrometer