102 Flashcards
What are the breakers set to on a resident 220V circuit?
40-50 amps
Who is allowed to install electrical systems for welding machines?
A certified electrician
Define arc?
An arc is created when there is enough amperage and voltage available at the electrode tip to overcome the natural resistance
What is the metal deposition rate?
It’s another term for burn off rate
What controls the core in a coil?
A moveable shunt
What body rates welding machine duty cycles?
National electrical manufacturers association (NEMA)
What is a electron?
Negatively charged particles that move through a conductor when current flowing
If a generator produces AC current what may it also be called?
An Alternator
What’s an inverter?
An inverter is a device that changes DC to AC
What is a rectifier?
A rectifier is a device that changes AC to DC
If you lengthen your stickout during a gmaw welding process what are you changing in the circuit?
You are adding resistance to the circuit which may lead to stubbing
When using straight polarity where is the majority of the heat?
2/3 of the heat will be in the electrode causing the electrode to melt
When using a CV machine how many rheostats will be on it?
2, one to set voltage and one to set wire speed
When looking at a volt-amp curve, if your line goes from volts and droops to amperage what kind of machine are you using?
Constant current
What two ferrous metals can’t be cut with a oxy-fuel torch?
Stainless steel and cast iron
What non ferrous metals can be identified by a spark test?
Nickel and titanium
What is the difference between red brass and yellow brass?
Red brass is more copper and less zinc, yellow brass on average 60% copper and 40% zinc
What are the two types of file hardness tests?
Rockwell and Brinell
This hardness test uses conical diamond penetrator applied to a specific load. The amount that the penetrator indents tells the hardness what test is this?
Rockwell
When flame testing metal what are you looking for?
The speed of melting, changes in colour, the appearance and action of slag, the appearance of the molten puddle, action if the molten puddle under the flame
If the heat identification number is removed from a plate what must be done?
Transfer it to the remaining plate
When metal is shipped what comes attached to the metal?
Mill report and metal specification tag
Define compressive strength
The resistance of material to a force that tends to deform or fail it by crushing
Define shear strength
The maximum load that a metal can take before it fractures across its section
Define tensile strength
The ultimate pull that a material will stand without fracture
Define yield strength
The stress point at which permanent deformation takes place
Define impact strength
The ability of a metal to withstand a sharp high velocity blow
What is the elastic limit?
The maximum stress the metal will endure before permanent deformation takes place
Define ductility
The ability of a material to stretch or deform under load without breaking or failing
Define brittleness
The tendency of a material to fail suddenly by breaking without any permanent deformation before failure
Define hardness
A materials ability to resist penetration or indentation
Define toughness
The ability of metal to withstand a rapidly applied load without breaking
Define elasticity
Is the ability of a metal to return to it original shape and dimensions once a load is removed
Define Malleability
A metals ability to be cold worked without a great deal of resistance