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Arc Welding. Ag I Welding Unit 2. Electrodes. Wide variety available to allow welder to do different jobs and weld in different positions Positions Flat, horizontal, vertical up and down, overhead Some electrodes are suitable for all positons , others only 1 or 2.
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Arc Welding Ag I Welding Unit 2
Electrodes • Wide variety available to allow welder to do different jobs and weld in different positions • Positions • Flat, horizontal, vertical up and down, overhead • Some electrodes are suitable for all positons, others only 1 or 2
Numberical Coding for Electordes • 4-5 digit number • Numbers preceded by the letter “E” to indicate that the number describes an electrode E 6011
Reading an Electrode • E 6013 • E-Electrode • 60—tensile strength (Thousands of pounds) • Tensile strength is the amount of pull the weld can withstand • 1—type of welding the electrode is capable of doing • 3—depth of penetration
5 digit Electrode Numbers • The same as a 4 digit except • First 3 numbers represent tensile strength • Fourth number represents welding position • Fifth number refers to depth of penetration
All Around Electrodes • 6011 • Most commonly used • Not easy for beginers to use to make an attractive weld • 6013 • Popular for beginning welders • Inexpensive • Easy to use
Personal Protection in Arc Welding • Helmet with a No. 10 shaded lens must be worn • Safety glasses under the helmet or on your person to be worn when chipping slag • Other PPE that was already discussed
Shielded Metal Arc Welding • Also called arc welding or stick welding • Shielded refers to the gaseous cloud that forms around the weld as the flux burns • The flux removes impurities and floats them to the top of the weld to form a layer called slag
Duty Cycle • The percentage of time that a welder can operate without overheating • Example: a 20 percent duty cycle welder should only weld 12 minutes out of every hour.
Electricity for Welders • Amps-the measure of the rate of flow in a conductor • A conductor is any material that permits current to move through it • Volts- the measure of electrical pressure • Watt-the measure of electrical energy available for work that can be done
Alternating and Direct Current • Alternating Current (AC)-current that reverses in direction of flow frequently. • In the U.S. power plants produce electricity that reverses direction of flow 60 times per second. This is referred to as 60-cycle current • Direct Current (DC) • Really generators • Current only flows in 1 direction • Can be set for both straight (neg.) and reverse (pos.) polarity
Welding Table and Booth • Metal Table • Curtains around table to protect others from the flash of the arc • If working outside the booth, set up portable curtains to protect others
Electrode Holders & Ground Clamps • Electrode Holder • Spring loaded device with an insulated handle • Used to grip the electrode • Ground Clamp • Spring loaded clamp • Not insulated like the electrode holder • Should be connected to the welding table
Arc Welder Temperture • Arc from a welder has a temp of 9000 ˚F