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4/30/2014

Welding electrodes

MMA /SMAW Electrodes Welding consumable for MMA consist of a core wire typically between 350 and 450mm length and from 2.5 6mm diameter. The wire is covered with an extruded flux coating.

MMA /SMAW Electrodes The function of flux coating are:1) To aid arc ignition 2) To improve arc stabilisation 3) To produce a shielding gas to protect the arc column 4) To refine and clean the solidifying weld-metal 5) To form a slag which protects the solidifying weldmetal 6) To add alloying elements 7) To control hydrogen content of the weld metal 8) To form a cone at the end of the electrode, which directs the arc

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MMA /SMAW Electrodes • Electrodes for MMA/SMAW are grouped depending on the main constituent in their flux coating, which in turn has a major effect on the weld properties and ease of use. • The common groups are given below:

MMA /SMAW Electrodes

MMA /SMAW Electrodes

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MMA /SMAW Electrodes E 7018 E Indicates that this is an electrode 70 Indicates how strong this electrode is when welded. Measured in thousands of pounds per square inch.

1 8

welding positions.

Indicates the coating, penetration, and current type used.

MMA /SMAW Electrodes • WELDING POSITIONS • 1 ALL POSITIONS • 2 Flat, Horizontal • 4 Flat, Horizontal, Overhead, Vertical (down)

MMA /SMAW Electrodes  CLASSIFICATION TABLE  Class Electrode Coating          

Penetration

E6010 Cellulose, Sodium Exxx1 Cellulose, Potassium Exx12 Rutile, Sodium E6013 Rutile, Potassium Exxx4 Rutile, Iron Powder Exxx5 Low Hydrogen, Sodium E7016 Low Hydrogen, Potassium Exxx7 Iron Powder, Iron Oxide E7018 Low Hydrogen, Iron Powder Exxx9 Iron Oxide, Rutile, Potassium

Deep Deep Medium Light Medium Medium Medium Medium Medium Medium

Current Type DCEP AC, DCEP AC, DCEN AC, DCEP, DCEN AC, DCEP, DCEN DCEP AC, DCEP AC, DCEN AC, DCEP AC, DCEP, DCEN

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GMAW

GMAW

GMAW ER 70S -6 for Steel MAG ERCU for copper MIG

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TIG

TIG electrodes • ER 308 L { Tig welding 18 % CR 8 Ni stainless steel} • ER309 { 22% Cr 12% Ni} stainless steel • ER 309 L stainless steel • ER 316 stainless steel • ER 70 S-G for steel • ER 70S-6 for steel • Er cu sn-A FOR COPPER (copper tin alloy)

Stainless steel

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Aluminum • • • •

ER 5356 alu mg ( GMAW - GTAW) ER 1100 pure alu ER 5183 High strength aluminum alloy ER4043 Alu Silicon

Oxy electrodes • • • • •

Milld steel Copper Aluminum Stainless steel Cast iron

Handling & Storage

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0xy acetylene • Weling flux • Welding flux are available in powder or paste. Functions: • Formation of a fluid pool • Protection against oxidation

Draying • Electrodes affected by moisture may be dried before use by putting them in a controlled draying oven for approximately one hour at temperature around 110-150 c

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