Introduction to practical application of wire feed welding.
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Transcript of Introduction to practical application of wire feed welding.
Introduction to practical Introduction to practical
application of wire feed weldingapplication of wire feed welding
MIG – Metal Inert Gas Welding
May be called GMAW (Gas Metal Arc Welding) Avoid cutting in drafty or windy conditions Molten pool is shielded by the inert gas envelope Joints are stronger, more ductile, and more
corrosion resistant Flux center wire has slag; Solid wire has no slag,
thus eliminating slag inclusion Welded metal does not readily distort
Power Supply
Gas Supply
Wire feeder
Gun and Whip
Process
MIG Machine Operation
Wire is fed at a pre-set rate Gas flows at about 35 cubic feet per hour
and is directed around the welding wire for shielding
Advantages Disadvantages Welding can be done in all
positions High rates of metal deposition Excellent filling ability for
poor-fit joints High weld Quality No electrode stub loss Less distortion due to narrow,
deep weld profile Easier process to learn and
use
Welding power source expensive
Shielding gas expensive Higher electrode wire cost Most machines require three-
phase input power Not as versatile as SMAW for
maintenance Welding cast iron Cutting Carbon arc torch
applications
Stationary
Portable
Integrated
Nonintegrated
Advantages and
Disadvantages
Adjustments
Containers Regulators
Ball and Dial indicators
Gases Materials Carbon dioxide Steel Argon Stainless Steel Helium Aluminum Oxygen
Types Integrated
Component
Advantages
Disadvantages
Parts Feed motor
Drive Assembly
Spool Assembly
Wire speed control
Computer controller
Gun Types Inline Handle
Gun Characteristics Wire Guide Tips Shielding Gas Nozzle Insulator Internal Gun wire
driver
Whip Characteristics Shielding Gas Sheath Liner Power feed
Wire Types Hard Wire (Solid) Dual Shield Flux Core
Polarity DCRP DCSP
Advantages Disadvantages
Advantages Disadvantages
TIG – Tungsten Inert Gas Welding
TIG
Welding process uses a non-consumable tungsten electrode to form an arc which is shielded by inert gas Filler rod may or may not be used AC or DC Argon or Helium gas used Torch needs current and inert gas to weld Ceramic cone protects electrode Air cooled or water cooled
Advantages of TIG
Clean welds – no flux Weld strength is high All position use Visibility is high Narrow beads – distortion is low No Spatter Weld all weldable metals Best for Aluminum and Magnesium Best for thinner metal
Disadvantages of TIG
Skill required – more complicated High Frequency interference may occur
(radios, TV’s, etc.)
Inert Gases for Shielding Argon
Cheap – comes from air Heavier than air – blankets
weld well Provides clean welding of
Aluminum and Magnesium Best with AC
Helium Arc voltage is greater Hotter arc Deeper Penetration Fast Speed Less Distortion May spatter more than Argon
Carbon Dioxide Cooling effect Low cost Produces Spatter Deep penetration Not same inert
characteristics as Argon and Helium