SMAW Shielded Metal Arc Welding Technical Terms AC

SMAW Shielded Metal Arc Welding

Technical Terms • • • AC Chipping Hammer CC CV DC DCEN DCEP DCRP DCSP Electrode holder SMAW

SMAW • Is a welding process in which the base metals are heated to fusion or melting temperature by an electric arc. • Arc is created between a covered metal electrode and the base metals • Base metals, arc, electrode, and weld are shielded from the atmosphere while welding. • Shielding Gas: used to protect the weld area from the atmosphere. Not pressurized. • As flux melts, creates the shielding gas.

SMAW

DC vs. AC • DC • Flows in one direction • DCEP creates deeper penetration then DCEN • DCEN caused electrode to melt faster and deposit filler metal at a faster rate. • DCEN heats the base more slowly then DCEP • More versatile because polarity can be changed AC 60 cycles per second Cycle= repeating events One direction 1/120 of a sec then reverses for 1/120 of a sec • Medium depth of penetration. • Meet most welding requirements, easy to use, cost less, used in industry, farm, and in home shop • •

SMAW Machines • Produce either CC or CV • SMAW require a CC

Chipping Hammer/ Wire Brush • Slag must be removed after each arc weld bead or pass is completed. • Slag is the hard, brittle material that covers a finished SMAW. • Use a Chipping hammer to chip slag away. Then further clean with a wire brush.

Electrode Identification • First two (sometimes three) numbers from the left = minimum tensile strength. • Last numeral = polarity • Second number from the right = recommended welding position/ type of weld. – 1 - all positions. – 2 - flat welding and horizontal fillet welds – 3 - flat position only – 4 - flat, horizontal, overhead, or vertical down welding