Metallurgy

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Shielded Metal Arc Welding

 

Some basics of Shielded Metal Arc Welding (SMAW), also known as "stick" or "arc" welding, are presented in the following sections.

Basic Operation

SMAW is a manual welding process that utilizes two electrodes connected to a constant current power supply. One electrode has a holder for a welding metal filler rod, the other has a clamp for connection to the workpiece. The filler rod is connected with a flux that provides protection from contamination by atmospheric gases. SMAW is suitable for welding many metals where the thickness of the work piece is at least 1/16".

Electrode Polarity

The terminology used to describe the polarity of the electrodes that are used to connect the welding rod and the work piece to the power supply are described in the following table.

 

Electrode Polarity
Current Terminolgy Previous Terminology Connection of Welding Rod Electrode Connection of Work Piece Electrode Operational Characteristics
Direct Current Electrode Negative (DCEN), DC-. DC Straight Polarity (DCSP) The clamp that holds the welding rod is connected to the negative terminal on the power supply. The clamp that is connected to the work piece is connected to the positive terminal on the power supply. Lower penetration, higher electrode burn-off rate than DCEP.
Direct Current Electrode Positive (DCEP), DC+. DC Reverse Polarity (DCRP). The clamp that holds the welding rod is connected to the positive terminal on the power supply. The clamp that is connected to the work piece is connected to the negative terminal on the power supply. Higher penetration, lower electrode burn-off rate than DCEN.

Filler Rods

Some of the main filler rods used for stick welding are described in the following table.

 

Filler Rods for Stick Welding
Type Application Description Polarity
E6010 Pipe and general structure welding. Deep penetration. Metal does not need to be completely clean. DC+
E6011 Same as E6010. Considered the easiest to use. E6010 modified for AC use also. AC or DC+
E6013 Low voltge. Less penetration than E6010. General purpose. AC, DC+ or DC-
E7018 Low, medium, and high carbon, and alloy steels. Better appearance, higher tensile strength than 6xxx rods. Can be used with 6010 as a base. AC or DC+