Direct current is an electrical current that flows in one direction only. True or False?
True
The words straight and reverse are in general use in the welding industry to describe welding polarities. True or False?
True
When using the GTAW process, the welding operator has four choices of welding current polarity. True or False?
False
List the two most basic parameters usually encountered in welding:
1.
2.
1. Current
2. Voltage
The necessary heat for GTAW is produced by an electric arc maintained between a _________ tungsten electrode and the part to be welded.
non-consumable
Shielding gas used in the GTAW process is an _________ gas which shields a tungsten electrode from the atmosphere.
inert
The greatest advantage of the GTAW process is that it will weld more kinds of metals and _________ than any other welding process.
metal alloys
The GTAW process itself does not produce ________ or ________ fumes.
smoke, injurious
The concentrated nature of the GTAW arc permits __________ control of heat input to the workpiece in a narrow heat affected zone.
pinpoint
The addition of _______ to the weld circuit made AC power sources fully capable of gas tungsten arc welding.
high frequency
In the United States the duty cycle of a welding machine is based on a five minute period. True or False?
False
The derating procedure is necessary only with DC GTAW, and not with AC GTAW. True or False?
False
Torches used for GTAW welding may be either water or air cooled. True or False?
True
Welding power is most often obtained from the local power company out of an/a _______ wall socket.
AC
The _________ of a welding machine must be within a proper duty cycle range.
output
DC welding machines require either_______ or _________ phase power.
single, three
Power sources which can be powered by either single or three power phase are called __________ power sources.
inventer
A _________ current machine is used in GTAW welding.
constant
On engine driven welding sources, it is the ___________ which produces alternating currents.
alternator
Most manufacturers produce machines that provide both ________ and _________ current from the same unit.
AC, DC
When the power switch on a welding machine is in the "On" position, the fan will operate. True or False?
True
Preheating of a material is most often achieved with the use of an oxyacetylene torch. True or False?
True
List the three positions of a high frequency switch on a power source.
1.
2.
3.
1. Start
2. Off
3. Continuous
List the types of stainless steel.
1.
2.
1. Magnetic type
2. Non-magnetic type
The primary overload circuit breaker provides ___________ against overloading of the main components of a welding machine.
protections
The _________ control is sometimes referred to as a dig.
arc/balance
The ___________ controls the length of time the shielding gas will continue to flow after the arc is broken.
post flow timer
Aluminum is very susceptible to _________.
contaminants
Mechanical cleaning can be done with __________ or wire brushes.
abrasive wheels
Chromium-nickle stainless steels are considered ___________ weldable.
readily
The scratch start method eliminates tungsten contamination. True or False?
F
The touch start method is used with the arc started briefly by placing the electrode in contact with the work and then quickly withdrawing the electrode.
F
The carbon start is used primarily in the critical welding applications. True or False?
False
The high frequency start method is the most popular of all arc starting methods. True or False?
True
The arc assist method uses a high voltage DC spike which is induced into the weld circuit. True or False?
True
List four types of joints which and be welded manually using the GTAW process.
1.
2.
3.
4.
1. Butt weld stringer bead
2. Lap joint
3. T-joint
4. Corner joint
When welding with __________ current using a balled end on the electrode, the arc length is normal one electrode diameter.
AC
Electrode extension may very from _______ with the gas cup to 1/2".
flush
Backing rings are made of __________ materials.
consumable
One of the most popular techniques for GTAW welding of the pipe joints is the _________ technique.
walking-the-cup
List five types of atmospheric shielding.
1.
2.
3.
4.
5.
1. Gas tungsten arc
2. Gas metal arc
3. Submerged arc
4. Shielded metal arc
5. Flux cored
List four kinds or shielding gases.
1.
2.
3.
4.
1. Argon
2. Helium
3. Hydrogen
4. Nitrogen
List five steps to be followed when you are ready to perform a GTAW operation using a typical regulator/flowmeter installation.
1.
2.
3.
4.
5.
1. Removing shielding gas cylinder cap
2. Open cylinder valve
3. Install regulator/flowmeter
4. Connect shielding gas hose
5. Adjust shielding gas flow
The chief factor influencing the effectiveness of a shielding gas is the gas ____________.
density
The purpose of both ________ and _________ is to prevent contamination.
preflow, postflow
Tungsten has a low resistance to current flow. True or False?
False
The ball tip is characteristic of pure tungsten. True or False?
True
The surface of a ball tip should be shiny and bright. True or False?
True
Needle pointed electrodes are usually preferred on thick metals. True or False?
False
Tungsten is harder than most grinding wheels. True or False?
True
List two types of tungsten electrodes which are usually preferred for direct current applications?
1.
2.
1. EWTh-1 type
2. EWTh-2 type
List four characteristics applicable to tungsten.
1.
2.
3.
4.
1. It is a very hard steel grey metal.
2. It is a highly refractory metal.
3. It does not melt or vaporize.
4. It has a melting point of 6170°F
5. It has a boiling point of 10,700°F
6. It retains its hardness even when red hot.
The tungsten electrode is said to be _________.
non-consumable
The _________ length tungsten is the most commonly used.
7th
Types of tungsten and tungsten alloy electrodes are classified according to the _________ makeup of the particular electrode types.
Chemical
Thoria is a _________ level radioactive material.
low
Tungsten electrodes for GTAW are identified by a _______ code.
color
The tungsten electrode is not melted and used as a __________ metal.
filler
One of the main considerations when selecting a tungsten electrode is ___________ current.
Welding
Grinding of electrodes is sometimes used to remove ____________.
contamination
List three factors to be considered in the standard of acceptability.
1.
2.
3.
1. Contour
2. Extent of fusion
3. Soundness
Give two reasons why metal alloys usually crack.
1.
2.
1. Physical restraint or both
2. High alloy content
List two types of cracking of steel welds.
1.
2.
1. Hydrogen-induced cracking
2. Reheat cracking
A member joint unable to __________ or _________ under stress is likely to crack.
expand, contract
What is S.M.A.W.?
Shielded Metal Arc Welding
What is G.T.A.W.?
Gas Tungsten Arc Welding
Name four types of tungsten.
1. 2% Throated
2. Pure
3. Lanthanum
4. 2% seriated
5. Zerconated
Name four parts of a T.I.G. torch?
1. Colet Body
2. Colet
3. Cup or Nozzle
4. Torch Head
What inert gas is used for T.I.G. welding?
Argon
What shade of lens range should be worn when arc welding?
9 through 12
What does the first two # mean on 7018 rod?
70,000 psi minimum tensile strength
What does the third # mean on 7018 rod?
Position to be welded in with this rod
What does the forth # mean on 7018 rod?
Type of coating and welding current
What is ER70S rod used for?
Tig welding
What is the type of flux used on 6010 rod?
Cellulose or organic- sodium
What code is B31.3?
ASME-Chemical Plant & Petroleum Refinery Piping
What code is B31.1?
ASME code for pressure piping
What code is B31.9?
ASME/ANSI - Building Services Piping
What code is B31.5?
ASME Refrigeration
Name the four passes in pipe welding?
1. Root
2. Hot
3. Filler
4. Cap
What does PQR stand for?
Procedure, Qualification Record
How long is a weld cert good for?
6 months
What does WPS stand for?
Welding Procedure Specification
What does AWS stand for?
Americal Welding Society
What does GMAW stand for?
Gas Metal Arc Welding
What does FCAW stand for?
Flux Core Arc Welding
What is the 6G Welding position?
45 degree Angle
What is the 5G welding position?
Horizontal
What is the 2G welding position?
Vertical
What degree is pipe Beveled for welding?
37 1/2 degree
Where does the + & - hook up when stick welding & what is the polarity called?
Electrode +(positive), Ground -(NEG) =
Reverse Polarity
Where does the + & - hook up when tig welding & what is the polarity called?
Electrode -(NEGAVTIVE), Gound +(POSITIVE) =
Straight Polarity
The words straight and reverse are in general use in the welding industry to describe welding polarities. True or False?
True
The ____________controls the length of time the shielding gas will continue to flow after the arc is broken.
post flow timer
When welding with ______ current using a balled end on the electrode, the arc length is normally one electrode diameter.
AC
List four types of joints which can be welded manually using the GTAW process.
1. Butt weld and stringer bead
2. Lap joint
3. T-joint
4. Corner joint
Give two reasons why metal alloys usually crack.
1. Physical restraint or both
2. High alloy content
Before starting any welding operation, you should make a __________________.
complete inspection of the equipment
Cylinders which contain _________ gas must be secured in an ________ position.
shielding, upright
A ___________ welding torch can be converted to a cutting torch or a grouping torch by replacing the welding tip (nozzle assembly) with a cutting attachment or a gouging tip.
combination
A multi-flame heating nozzle is basically a large _________ tip.
welding
Welding tips are available in a variety of sizes determined by the ______ size of the orifice in the flame end of the tip.
drill
Cutting tips are designed with several small ________ surrounding a larger _______ in the center.
orifices, orifice
List four causes of reverse flow of gases.
1. Damaged tips or nozzles
2. Incorrect torch lighting procedures
3. Loss of pressure in one line
4. Cylinder emptying while in use
You should wear safety glasses with ___________ or goggles under helmet-type shields to protect your eyes from flying particles.
side shields
What is the Amperage range that 1/8th E-6010 stick electrodes should be welded?
75 to 125 AMPS
What is the amperage range that 3/32" E7018 stick electrodes should be welded?
70 to 100 AMPS
In the UA-21 Weld Test Specification listed under PIPE COUPON MATERIAL, the Pipe Size listed says NPS 2, XXS, and 0.436 Wall. What does NPS stand for?
Nominal Pipe Size
Is it permissible to grind on the UA weld test? YES or NO
YES
How far back should a welder clean a coupon in preparation for a weld test?
1"
What is the maximum misalignment permissible on a weld test coupon?
1/16"
E-7018 welding electrode to be welded with
AC-DCEP current
Which group of Electrode Characteristics is E-7018 Electrode in?
Fill Freeze
What type of welding process is ER70S-2 welding Rod used for in the GTAW process?