120103c Lyles Review moved

Question 1

The preferred way of measuring shielding gas flow is:
A) pounds per square inch (kilograms per square centimeter)
B) pounds per hour (kilograms per minute)
C) cubic feet per hour (liters per minute)
D) surface feet per hour (surface meters per minute)

Answer 1

C) cubic feet per hour (liters per minute)

Question 2

Inert gas welding flowmeters are calibrated in liters per minute (cubic feet per hour), which measure:
A) volume rate of gas flowing
B) capacity of gas flowing
C) pressure of gas flowing
D) density of gas flowing

Answer 2

A) volume rate of gas flowing

Question 3

Shielding gas flow is measured in:
A) PSI
B) CFH
C) SFM
D) RPM

Answer 3

B) CFH

Question 4

The shielding gas flow valve is operated by a:
A) toggle switch
B) solenoid
C) pressure relief valve
D) foot control

Answer 4

B) solenoid

Question 5

A flow meter is calibrated for:
A) all inert gases
B) fuel or nonfuel gases
C) all gases used for G.M.A.W.
D) a specific type of gas

Answer 5

D) a specific type of gas

Question 6

Flow meters are calibrated for each type of shielding gas because each gas has a different:
A) ionization potential
B) thermal or electrical conductivity
C) electrical resistance
D) specific gravity or gas density

Answer 6

D) specific gravity or gas density

Question 7

The approximate range for shielding gas flow, using .035 steel wire and short circuit welding is
A) 4 - 7 L/min (10 - 15) cubic ft./hr.
B) 7 - 23 L/min (15 - 50) cubic ft./hr.
C) 14 - 19 L/min (30 - 40) cubic ft./hr.
D) 24 - 26 L/min (50 - 55) cubic ft./hr.

Answer 7

B) 7 - 23 L/min (15 - 50) cubic ft./hr.

Question 8

What is the most accurate regulator/flowmeter?
A) floating ball type
B) dual gauge type
C) inverted orifice type
D) the cheapest one available

Answer 8

A) floating ball type

Question 9

What type of hose should be used with helium shielding gas?
A) plastic type hoses
B) rubber type hoses
C) garden type hoses
D) flexible copper lines

Answer 9

A) plastic type hoses

Question 10

What is the purpose of the shielding gas in the gas metal arc welding process?
a) reduce the carbon content in the weld metal
b) protect the weld from the atmospheric contaminants
c) combine with the weld metal to increase ductility
d) unite with oxygen which will increase weld properties

Answer 10

b) protect the weld from the atmospheric contaminants

Question 11

When oxygen and nitrogen become mixed in the molten weld metal, they:
a) strengthen the metal
b) are very harmful to the weld
c) help ductility of the weld zone
d) increase the yield point of the metal

Answer 11

b) are very harmful to the weld

Question 12

The addition of oxygen to argon will cause temperature of the molten metal to:
a) decrease
b) increase
c) stabilize
d) oxidize

Answer 12

b) increase

Question 13

When using COshielding gas with GMAW welding, the transfer of the filler metal is by:
a) spray transfer only
b) globular and plasma transfer
c) short circuit and globular transfer only
d) pulsed current and spray transfer

Answer 13

c) short circuit and globular transfer only

Question 14

What is the main purpose of adding oxygen
(1-9%) to argon when welding mild steel or stainless steel?
a) eliminates porosity
b) gives better penetration
c) allows weld metal to wet out at the toes
d) allows for a greater selection of filler wire to be used

Answer 14

c) allows weld metal to wet out at the toes

Question 15

Identity the toxic fume created when carbon dioxide is subjected to the heat of the arc in GMAW and FCAW.
a) lead
b) carbon monoxide
c) hydrocarbon
d) argon

Answer 15

b) carbon monoxide

Question 16

GMAW, with a carbon dioxide shielding gas, requires good ventilation because of emission of:
a) excessive smoke
b) carbon monoxide
c) excessive sparks
d) excessive heat

Answer 16

b) carbon monoxide

Question 17

The shielding gas most commonly used for GMAW of non-ferrous metals is:
a) carbon dioxide
b) nitrogen
c) helium
d) argon

Answer 17

d) argon

Question 18

Which shielding gas is used primarily for welding mild steel?
a) carbon dioxide
b) nitrogen
c) helium & argon
d) argon

Answer 18

a) carbon dioxide

Question 19

If 1% to 9% oxygen is added to the argon shielding gas, it is to:
a) reduce spatter
b) increase deposition rate
c) improve wetting action
d) reduce welding costs

Answer 19

c) improve wetting action

Question 20

Which of the following gas blends tends to reduce high crowned weld beads on stainless steels?
a) helium-carbon dioxide
b) argon-carbon dioxide
c) nitrogen-carbon dioxide
d) helium-argon-carbon dioxide

Answer 20

d) helium-argon-carbon dioxide

Question 21

A disadvantage of using carbon dioxide with GMAW is that:
a) porosity may be a problem
b) undercut at the toe of the weld occurs
c) spatter is much more common
d) it is not readily available

Answer 21

c) spatter is much more common

Question 22

If pure argon is used in the gas metal arc welding process when welding stainless steel, it may cause the weld to have:
a) undercut
b) flat bead contour
c) a vertical interface
d) excess porosity

Answer 22

a) undercut

Question 23

Helium is used primarily as a shielding gas for which of the following metals?
a) aluminum and copper
b) mild steel and stainless steel c cast iron and cast steel
d) plain carbon steels and low alloy steels

Answer 23

a) aluminum and copper

Question 24

Argon-oxygen mixtures are common shielding gas for the welding of what type of material?
a) aluminum
b) magnesium
c) copper alloys
d) stainless steels

Answer 24

d) stainless steels

Question 25

Which of the following GMAW modes would produce the most spatter? a) globular transfer and carbon dioxide b) short circuiting transfer and argon carbon dioxide mix c) spray transfer d) spray transfer and argon carbon dioxide mix

Answer 25

a) globular transfer and carbon dioxide

Question 26

With which shielding gas is spray transfer NOT possible? a) argon-oxygen b) 10% CO2 argon mix c) argon d) carbon dioxide

Answer 26

d) carbon dioxide

Question 27

Which of the following GMAW shielding gases would require the highest flow rate? a) argon b) helium c) carbon dioxide d) nitrogen

Answer 27

b) helium - because its lighter than air

Question 28

Which of the following has the greatest effect on the flow rate of shielding gases? a) diameter of electrode, wire speed, climatic conditions b) position of weld, thickness of material, polarity of current c) type of material, diameter of rod, amount of current d) type of gas, type of material, position of weld

Answer 28

d) type of gas, type of material, position of weld

Question 29

29. Which gas has the highest weight (specific gravity)? A) hydrogen B) helium C) argon D) nitrogen

Answer 29

C) argon

Question 30

The effect of adding small amounts of 02 to argon shielding gas is: A) it gives less oxidization B) it gives less porosity C) it gives the puddle a higher level of viscosity D) it improves puddle fluidity

Answer 30

D) it improves puddle fluidity

Question 31

What type of shielding gas is preferred for GMAW short circuit welding of austenitic stainless steels A) 75% argon, 25% CO2 B) 90% helium, 7.5% argon, 2.5% CO2 C) argon D) helium

Answer 31

B) 90% helium, 7.5% argon, 2.5% CO2

Question 32

It is recommended that carbon dioxide cylinders be recharged when the pressure gets below: a) 175 psi b) 200 psi c) 225 psi d) 250 psi

Answer 32

b) 200 psi

Question 33

When there is a buildup of frost on the carbon dioxide flowmeter, it is recommended that you should: A) install a line heater B) increase the gas flow C) change the machine setting D) increase the amperage

Answer 33

A) install a line heater

Question 34

What shielding gases are generally used with the FCAW process? A) nitrogen and carbon dioxide B) argon and nitrogen C) argon and helium or combinations of these two D) carbon dioxide and argon or combinations of these two

Answer 34

D) carbon dioxide and argon or combinations of these two

Question 35

When using FCAW process with an external shielding gas, which gas has the least amount of spatter A) carbon dioxide B) argon and carbon dioxide C) argon and oxygen D) argon

Answer 35

B) argon and carbon dioxide

Question 36

When using FCAW, which shielding gas or gas mixture gives a smooth arc, very little spatter and good appearance on plain carbon steel? A) argon B) CO2 C) helium D) 75% argon 25% CO2

Answer 36

D) 75% argon 25% CO2

Question 37

When FCAW requires an external shielding gas, which shielding gas is most commonly used? A) carbon dioxide B) helium and carbon dioxide C) argon and hydrogen D) argon

Answer 37

A) carbon dioxide

Question 38

When FCAW requires an external shielding gas, which gas gives the best penetration and low cost? A) carbon dioxide B) argon and helium C) argon and oxygen D) argon

Answer 38

A) carbon dioxide

Question 39

Which shielding gas is most commonly used in flux core arc welding? A) argon B) helium C) CO2 D) 25% nitrogen, 75% argon

Answer 39

C) CO2

Question 40

Which characteristic best describes CO2 shielding gas with FCAW? A) good surface cleaning B) deeper penetration & lower cost C) broad bent contour D) smooth arc

Answer 40

B) deeper penetration & lower cost

Question 41

What shielding gases are generally used with the FCAW process? A) nitrogen and carbon dioxide B) argon and nitrogen C) argon and helium or combinations of these two D) carbon dioxide and argon or combinations of these two

Answer 41

D) carbon dioxide and argon or combinations of these two

Question 42

The effect of adding small amounts of 02 to argon shielding gas is: A) it gives less oxidization B) it gives less porosity C) it gives the puddle a higher level of viscosity D) it improves puddle fluidity

Answer 42

D) it improves puddle fluidity