TPC 419 Arc Welding Operations Flashcards
SMAW is started by touching the end of an electrode to the base metal, then lifting the electrode about _______ in to make an arc. The arc produces temperatures in the range of _______ F
1/8; 1000
1/4; 10,000
1/2; 500
1; 1000 
1/4; 10,000
SMAW electrodes are classified by their
Color
Core material
Feed rate
Length
Core material
Which of the following items offers protection from arc flash?
Cotton clothing
Respirator
Safety glasses
Welding helmet
Welding helmet
Important factors to consider when selecting SMAW electrodes include the
Composition of the base metal
Environmental conditions
Length to be welded
Type of joint
Composition of the base metal
Welding electrodes are identified by the letter _______ followed by a number. The first two digits of the number identify the ______
B; Amount of current required
E; Tensile strength of the deposited metal
R; Special characteristics of the electrode
W; Welding position for which the electrode is suited
E; tensile strength of the deposited metal
When selecting an electrode for SMAW, you should consider the current range, which depends mainly on the
Diameter of the electrode
Length of the electrode
Thickness of the covering
Welding position
Diameter of the electrode
What kind of covered electrode allows you to use high welding current without causing excessive penetration?
Iron powder
Low hydrogen
Mineral covered
Titania covered
Iron powder
Electrodes covered with ______must not be allowed to become too dry.
Cellulose
Iron powder
Manganese oxide
Titanium oxide
Cellulose
In which of the following is electrode metal deposited when direct contact occurs between the electrode and the base metal?
Globular transfer
Pulsed gas
Short circuit
Spray transfer
Short circuit
Which of the following is a common GMAW shielding gas?
Argon
Hydrogen
Nitrogen
Oxygen
Argon
The best shielding gas for a flat or horizontal GMAW weld is one that (is)
Conducts heat poorly
Conduct heat well
Heavier than air
Lighter than air
Heavier than air
Generally, the main consideration when selecting an electrode wire for a GMAW application is the
Base metal composition
Joint condition
Shielding gas used
Welding position involved
Base metal composition
When preparing to operate a GMAW gun, position is nozzle about _______ in. above the worK and tilt it about _______• off vertical in the direction of the welding
1/4; 20
1/2; 45
3/4; 20
One; 45
3/4; 20
GTAW equipment and supplies may include which of the following?
AC welding machine
Air-cooled torch
Consumable electrodes
Flux Rods
Air-cooled torch
The purpose of the GTAW electrode is to
Conduct electricity
Emit shielding gas
Provide filler metal
Provide flux
Conduct
When using GTAW to weld a very thick piece of low-carbon steel, you should use ______ as shielding gas and______ as the filler metal
Argon; copper alloy
Carbon dioxide; carbon steel
Helium; low carbon steel
Nitrogen; stainless steel
Helium; low carbon steel
When welding stainless steel‘s with GTAW, you should use current, and when welding aluminum, you should use current
ACHF; DCEN
ACHF; DCEP
DCEN; ACHF
DCEP; DCEN
DCEN;ACHF
Which of the following is an advantage of GTAW over other welding processes?
Can weld a large variety of metals
Is easily portable
Requires little school to perform
Requires no filler metal
Can weld a large variety of metals
Resistance welding uses electric current and ______ to join metals
Continuous electrodes
Electron beams
Ionized gas
Pressure
Pressure
Submerged arc welding is unique in that the electricity passes through a layer of
Filler metal
Flux
Ionized gas
Plasma
Flux
Plasma arc welding is unique in that the electricity passes through a layer of
Filler metal
Flux
Ionized gas
Water
Ionized gas
Which of the following is part of conventional friction welding?
Electric heating
Flywheel
Spinning part
Vibrating head
Spinning part
One advantage of ultrasonic welding over other types of welding is that it
Can make a weld 200 times deeper than it is wide
Can make leak-tight joints in thin materials
Can weld very thick metals
Requires no special equipment
Can make leak-tight joints in thin materials
Preheating parts before welding them reduces the
Distortion of the welded structure
Energy required for welding
Filler metal needed
Time required for welding
Distortion of the welded structure
Uneven or rapid heating during welding causes ______ in metal, which can in tern cause_____
Contraction; deformation
Contraction; melting
Expansion; deformation
Expansion; Melting
Expansion; deformation
The heat-affected zone of a metal can undergo permanent changes in its
Chemical composition
Color
Mechanical properties
Weight
Mechanical properties
What should be your primary consideration when deciding whether or not preheating of a ferrous metal part is necessary?
Ambient temperature
Carbon content
Electrode size
Part thickness
Carbon content
Which of the following conditions indicates a possible need for postheating?
Nonferrous metal
Rapid cooling after preheating
Welded on both sides
Welded on one side only
Rapid cooling after preheating
Ferrous metals are those metals that are ______ based
Carbon
Copper
Iron
Lead
Iron
Which of the following is a step in edge preparation for ferrous metals?
Aligning the edges
Cutting or gouging the edge
Marking the weld’s location
Removing Knicks and burrs
Cutting or gouging the edge
The most common method used for welding cast iron is
FCAW
GMAW
GTAW
SMAW
SMAW
Cast iron can be welded at low currents in any position with ______ SMAW electrodes
Aluminum-bronze
Cast-iron
Nickel-based
Phosphorus-bronze
Nickel-based
When welding alloy steel’s, you should use electrodes and current
Low-hydrogen; DCEP
Mildsteel; DCEN
Phosphorus-bronze; DCEN
Thoriated tungsten; DCEP
Low-hydrogen; DCEP
An important property of aluminum that you should be aware of is that it
Attracts a magnet
Flares and burns when heated
Readily forms an oxide coating
Turns red when heated
Readily forms an oxide coating
What is the best way to determine the kind of metal a part is made of?
Contact the part manufacture
inspect the part visually
Perform a chip test
Use in nitric acid test
Contact the part manufacturer
The most widely used are processes for cutting nonferrous metal is
Air carbon
Carbon
Plasma
Shielded metal
Air carbon
Using a chemical cleaner to clean aluminum before welding slows the rate at which the
Base metal melts
Electrode is consumed
Flux corrodes
Oxidation reforms
Oxidation reforms
When welding nickel, use the process and a power supply
GTAW; DCEN
GTAW; DCEP
SMAW;DCEN
SMAW;DCEP
GTAW;DCEN
Compared to the other kinds of pipe joints, welded pipe joints are
Easier to construct
Heavier
More expensive
Stronger
Stronger
Welding pipe in high-pressure systems requires that a welder have which AWS qualification level?
AR – 1
AR – 2
AR – 3
AR – 4
AR – 1
Which of the following is the most widely used pipe welding process?
GMAW
GTAW
SAW
SMAW
SMAW
Weld backup rings are special accessories that help prevent______ in pipe welding
Icicles
Poor fitup
Underbead cracking
Warping
Icicles
The need for preheating and postheating when welding pipe depends on
Base metal composition and pipe thickness
Pipe diameter and weld process
Pipe thickness and pipe diameter
Weld process and weld orientation
Base metal composition and pipe thickness
Wear caused by grinding or scratching action of hard particles is called
Abrasion
Corrosion
Erosion
Friction
Abrasion
Cross-checking is desirable in some surfacing deposits because it
Improves overall appearance
Prevents slag inclusion
Provides additional strength
Relieves residual stress
Relieves residual stress
The hardest, and most where resistant hard facing metals are
High-alloy Ferrous
Low-alloy Ferrous
Nonferrous
Tungsten carbide
Tungsten carbide
The technique of _____ is especially useful for building up thin-edged tools.
Automatic hard facing
Manual arc hard facing
oxyacetylene hard facing
Thermal spraying
Oxyacetylene hard facing
Most automatic hard facing is done with______ machines
FCAW
GMAW
SAW
SMAW
SAW
In shielded metal arc welding, the shield is made of
Alloy metal
Flux
Gas
Oxides
Gas
In SMAW, it is important to understand that lengthening the arc _____the resistance, which _______ the temperature.
Decreases; decreases
Decreases; increases
Increases; decreases
Increases; increases
Increases; increases