Arc Welding (basic Principals) Flashcards
What is the average temperature of an arc?
6500 degrees F (4000 degrees Celsius) and above
What is it called when only joining two pieces of metal together with no filler?
Autogenous welding
What are the 3 basic types of arc welding?
Gas metal arc welding (GMAW)
Sheild metal arc welding (SMAW)
Gas tungsten arc welding (GTAW)
Why do welds sometimes need to be protected from the air during the welding process?
Elements in the atmosphere react with the molten metal and cause defects in the weld
What is the purpose of shielding gas?
To protect the weld from air
What is the two methods of providing shielded gas?
Supply the gas from a compressed splinter
Melt flux at the weld site
What is a process that uses both methods of shielding gas’s called?
Dual shield
Which welding methods most commonly use a supplied gas
Gas Metal Arc Welding (GMAW)
Gas Tungsten Arc Welding (GTAW)
What method of welding commonly uses a flux covered electrode to produce a shielding gas?
Shield Metal Arc Welding (SMAW)
What are the two categories of shielding Gases?
Inert
Semi-Inert
What type of gas does not react with anything around it?
Inert Gas
What can happen if you have an improper welding gas? (3)
Porous weld
Weak weld
Excessive spatter
What are the two main examples of an inert gas?
Helium
Argon
Where is Argon commonly used in terms of welding?
Non ferrous metals
( aluminum, magnesium, and alloys of the two )
What gas is commonly used with carbon steels?
Carbon Dioxide (C02)
What welding gas has the deepest penetration?
Carbon Dioxide (C02)
What is Argon (A) and Carbon Dioxide (C02) typically used on?
Mild steels, low alloy steel, and sometimes stainless steel
What is Argon (A) and Helium (He) typically used on?
Non ferrous metals
(Typically aluminum, magnesium, and copper)
Where are Argon (A) and oxygen (O) Typically used?
Typically on stainless steels
Also can be used on mild steel, or alloy steels
Aleternating current (AC) is also called what?
Reversing
What electrical circuit has both positive and negative values alternating?
Alternating current
(AC)
Or called reversing
What is anther name for Direct current DC?
Constant current
What is the name of an electrical current that flows in one direction only, either positive or negative but no change?
Direct current
(DC)
Or constant current
What is another term to describe ampere (amp)?
Flow volume
What is amp?
A unit of measurement
What is the name for the unit of measurement used in expressing the rate of current flow?
Ampere (amp)
Or flow volume
Describe current flow
The measurement of electron movement in an electrical circuit measured in amps
What is another way to describe Voltage?
Pressure
The electrical pressure or force that causes current to flow is called what?
Voltage
What is the electrical symbol for voltage?
E
What does NOT flow in a circuit?
Voltage
What DOES flow in a circuit?
Current (amperage)
What is arc voltage in terms of welding?
The voltage output of the machine while welding is being preformed
The force that pushes the current (amps) through the welding cables and maintains the arc
What is the name of the voltage output of the machine while welding is being preformed called?
Arc voltage
What does Herz (Hz) refer to?
How many cycles occur per second
What is a sine wave?
The way that electricity moves through a system in a visual form
What is a single phase power supply?
A power supply that only has 1 sine wave
What type of sine wave is this?
Single phase alternating current (AC) sine wave
What type of sine wave is this?
Three phase Alternating Current (AC) sign wave
What is the benefit of multiple phase sine waves?
When one phase of power reaches zero another can still supply power
What is the term used to describe when a filler metal is not used?
Autogenous welding
(Fusion)
Why is it called electric arc welding?
The welding occurs when a flow of electricity jumps a gap between the electrode and the workpiece forming the arc
Describe what shielding gas does for welding
Protects the weld area by omitting the atmosphere from the welding zone
I’m the process of GMAW (gas metal arc welding) the electric arc is produced between what?
A progressively fed electrode wire and the base metal
In North America what is the frequency of DC supplied by electrical companies?
It’s not. Electricity is supplied in AC from suppliers at 60
At under 60 amps what shield should you be using?
7
What are the 3 power sources for arc welding?
Transformers
Inverters
Generators
What are the two classified groups for welding machines?
Constant current
Constant voltage
What class do shielded metal arc welding machines fall into?
Constant current
What group does gas metal arc welding machines fall into?
Constant voltage
What machine maintains the set amperage and varies the voltage?
Constant current
What machine maintains the set voltage and varies the amperage?
Constant voltage
What welding machine is the cheapest to set up but have limited electrode selection?
Transformers
What are the benefits to an inverter welder? (3)
Highest flexibility
Multi purpose
Allow very fine control of the welding current and arc characteristics
What is duty cycle?
A rating expressed as a percentage that a machine can be run at continuously over a 10 minute period
How much can a welding machine rated for 300 amps and a 60% duty cycle produce?
300 amps for 6 minutes every 10 minutes
What welding machine has the lowest start up cost?
Transformer
When welding cables become larger than 1 how are they written?
1/0
2/0
Etc
Is a 4 cable or a 2 cable larger?
2
How does the amount of amperage effect a welding cable?
Larger amperage = larger cable
How does the distance from a welding machine affect the welding cable?
Distance from the machine is crease so does the welding cable size
What are the 5 key points for controlling a weld?
Heat (Amperage)
Distance (arc length)
Angles
Travel speed
Manipulation
What does the amperage needed for a welding project depend on? (3)
Base metal thickness
Position of welding
Electrode type and diameter
What are the 5 basic joints that may be welded?
Butt
Lap
Corner
T
Edge
What are the four weld types?
Surfacing
Plug or slot
Fillet
Groove
With non destructive testing methods what does the letter designation AET mean?
Acoustic emission test
With non destructive testing methods what does the letter designation ET mean?
Eddy current (electromagnetic test)
With non destructive testing methods what does the letter designation LT mean?
Leak test
With non destructive testing methods what does the letter designation MT mean?
Magnetic Particle test
With non destructive testing methods what does the letter designation NRT mean?
Neutron Radiographic Test
With non destructive testing methods what does the letter designation PT mean?
Penetrant Test
With non destructive testing methods what does the letter designation PRT mean?
Proof test
With non destructive testing methods what does the letter designation RT mean?
Radiographic test
With non destructive testing methods what does the letter designation UT mean?
Ultrasonic test
With non destructive testing methods what does the letter designation VT mean?
Visual Test
What is “straight polarity”?
Electrode negative
How does straight polarity affect the electrode?
Electrode negative
Burns hotter
Penetration is shallower
Wider metal flow
What is reverse polarity?
Electrode positive
How does reverse polarity affect the electrode?
Electrode burns cooler
Narrower metal flow
Penetration deeper
Control improved
Which type of welding has the best penetration?
GMAW-P
What welding process has a low hum?
GMAW-P
What welding process sounds like a light hiss?
GMAW-S
What is the electrode in straight polarity?
Negative
What is the electrode in reverse polarity?
Positive
What is hotter in straight polarity, the base or electrode?
Electrode
What is hotter in reverse polarity the base or electrode?
Base
