SEMI-AUTO 1
Advantages of GMAW what are they
Weld metal cleaner ( fewer oxide inclusion)
No slag removal,high quality deposition,reduced heat input,wide variety of materials.
Which mode of metal transfer is best for applications involving thin material and where fit up is poor
short circuit
For applications requiring a high deposition rate, what is the minimum amount of argon needed to achieve an axial spray transfer?
85%
In MCAW what is the main component of the core chemistry?
Iron powder
Which gas can be used with FCAW to improve arc stability in applications where welding is done inside?
Carbon Dioxide
When using pulsed GMAW,what happens if the wire feed speed is increased?
The pulse frequency and amperage are also increased
Why are the flux additives in the metal core of MCAW wires researched and changed often?
To comply with updates to safety restrictions
Which welding process establishes an arc beneath a bed of granular flux with the heat of the arc melting the base metal and flux?
SAW( Submerged arc welding)
IN what position can Submerged arc welding be used?
Flat and horizontal
Most wire fed processes use which type of power source?
CV Constant Voltage
When using a CV power source what happens when arc length changes?
The voltage remains the same and the current increases
How is flux applied to the welding arc during SAW?
Flux is gravity fed from the hopper to the nozzle at the work.
What type of liner does you welding gun use for welding aluminum and stainless steels?
Teflon
Flow rates of gas are measured in what units
Litres per minute(LPM) or cubic feet per hour(CFM)
What precautions are need when welding inside a vessel with the wire fed process.
Gas monitor testing for air quality. Hole watch if a confined space.Air movers to move smoke.Certified plan for confined space work.Confined space training.
Is Argon an inert shielding gas?True or False
(True) It will not mix with the materials in the weld zone. Denser than air good for flat,horizontal,and vertical down.
When welding aluminum Helium is used to increase the heat of the arc and increase penetration. TRUE or FALSE
True
The use of Ar-Co2 gases cause less oxidation of _________and ______________
Manganese(MN)and silicon (SI)
What is one problem when storing wire in a unheated environment.
Moisture in the wire make it unusable.
Two most common types of wire for welding aluminum are ?
ER 4043 and ER 5356
What is the flux to metal ratio in a self shielded wire?
35%
What is inductance ?
It controls the rate at which the current increases and decreases during a short circuit .
What is back ground amperage?
Control of current rise and fall during the pulse cycle is used to control droplet shape
Two reasons why stringer caps are preferred?
They keep the heat input levels down.They refine the grain structure in the (HAZ) Heat affected zone
Cap pass reinforcement can be a maximum of how much.
1/8 inch