Shielded Metal Arc Welding. Arc Welding?. Uses electricity for heat. Arc Welding ?. Electrodes (Rods) covered with flux. Arc Welding?. Gas cloud (Shield) around the metal during welding. Arc Welding. Heat for arc welding comes from electricity. Arc Welding. - PowerPoint PPT Presentation
Citation preview
Shielded Metal Arc Welding
Arc Welding?•Uses electricity for heat
Arc Welding ?•Electrodes (Rods) covered with flux
Arc Welding?•Gas cloud (Shield) around the metal during welding
Arc Welding•Heat for arc welding comes from electricity
•Welder = machine used for welding that produces a current
Arc Welding
•Arc = discharge of electricity
•Weldor = a person who welds
Arc Welding
•Electrodes = flux coated metal rods
Arc Welding
Arc Welding•Electrode Holder = spring loaded device with insulated handles used to grip the electrode
•Ground Clamp = spring loaded clamp that is attached to an electrical cable
Arc Welding
•Chipping Hammer = steel hammer with a sharp edge/point and a wire brush
Arc Welding
Arc Welding•Helmets = cover your head and neck region-- a # 10 shield is required
•Safety Glasses = must be worn under the welding helmet
Arc Welding
•Welding Gloves = insulated gloves worn to protect hands from heat and sparks (not 100%)
Arc Welding
Welding Process
W = Watts = measure of energy available
W = V X A
V = Voltage = measure of electrical pressure
W = V X A
A = Amp = rate of flow of current
W = V X A
Temperature
•Arc can be up to 9000 degrees F.
Temperature• Depends on:
–Arc Length–Electrode type–Amp Setting–Base Metal
Duty Cycle
•The percentage of time that a welder can operate without overheating
•The number of minutes out of 60 that a welder can operate at full capacity
Duty Cycle•The number of minutes out of 60 that a welder can operate at full capacity
AC/DC•AC
–Alternating Current
–Rev. Direction
AC/DC•AC
-U.S. 60 Cycles per second
AC/DC•AC
–Use Transformers to step-down voltage and increase amps
AC/DC•DC
–Direct Current–Electricity flows in one direction
AC/DC•DC
–Straight vs. Reverse Polarity
–Use Generators to produce the DC
Electrode Coding NEMA
•Uses color coding on the rods
• 3 areas on the rod
Electrode Coding AWS
•# coding system on the rods
•Each # stands for something
E6013•E = Electrode
•60 = Tensile Strength
•1 = Welding Position
•3 = Welding Current
Flux
•Shields Outside gasses
Flux
•Combines with metal impurities
Flux•Forms Slag
•Makes and Maintains Arc
What Affects a Weld Bead???
•Temp of Base Metal
–Adjust your Amps
What Affects a Weld Bead???
•Electrode Diameter and Flux Type
What Affects a Weld Bead???
•Amps–Select according to the thickness of your metal