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

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

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

What Affects a Weld Bead??? Arc Length –“Frying Bacon”

What Affects a Weld Bead??? Electrode Angle –10 to 15 degrees from vertical

What Affects a Weld Bead??? Speed of Travel –Even across the metal

Arc Welding Safety Weld on a proper surface Fire Exting./blanket nearby

Arc Welding Safety Surrounding area??? Wear all safety equipment/gear