SMAW WELDING

KELOMPOK 131. WIDYA NANDA PRASTIAWAN2. YA ARIF KHOIRUR RHOHIM3. ZAKARIA BAGUS AMINANTA

WELDING

welding process is the process of switching between metal or non-metal that produces an integral part, by heating the material to be spliced to the specific welding temperature, with or without pressure, and with or without filler metal

Smaw welding

SMAW (Shielded Metal Arc Welding) is a welding process to melt the base material using heat from electricity between cover metal (electrode).

The main welding tools

SMAW is a manual work with the equipment includes a power source, electrode wires (electrode cable), work cable (cable work), electrode holder, work clamp and electrode. Electrode and the work system is part of the electrical circuit. The series began with a power source and cables, including welding, electrode holder, the connection of the workpiece, the workpiece (weldment), and welding electrodes.

The main welding tools

As in the AWS (American Welding Society), the principles of SMAW is using the heat from the arc to melt the base metal and the tip of a consumable covered electrode voltage 23-45 volt electricity used, and used for melting up to 500 amperes of electrical current commonly used range between 80-200 amperes

In welding with SMAW method, welding begins when an electric arc is struck to make contact between the tip electrode and the work system. Intense heat of the arc melt the tip of the electrode and the work surface near the bow. Small bubbles of molten metal rapidly formed at the tip of the electrode, and then transferred through the arc stream into the molten weld pool.

polarity of welding

SMAW welding process with methods distinguished by the type of current includes AC and DC current, DC current which distinguished on DCEN (straight polarity direct polarity-) and DCEP (reverse polarity - the polarity is reversed). The difference between SMAW with AC and DC current are as follows:

AC Polarition

For AC (Alternating Current) voltage drop on the cable does not much influence, less suitable for weak currents, not all types of electrodes can be used, the arc starting is more difficult, especially for small electrode diameter, the pole can not be exchanged, not a bow arc problem.

DC Polarition

on the current DC (Direct Current) voltage drop is sensitive to cable length as short as possible, can be used for small currents with a small electrode diameters, all types of electrodes can be used, the arc starting easier, especially for small currents, the pole can be exchanged, bow arc sensitive to the the tip, or a corner lot indentation part.

DCEN Polarition

DCEN (Straight Polarity), the base material or the material to be welded is connected to the positive pole (+) and elektrode connected to the negative pole (-) DC welding machines. This way the electric arc moves from the electrode to the base material so that the collision of electrons are in the base material resulting in 2/3 the heat is in the base material and the electrodes are in the third heat. This will result in melting of the base material more than elektrode so that the weld has deep penetration, so that both are used in welding a slow, narrow areas and for thick plates.

DCEP Polarition

In DCEP (Reversed Polarity), basic material connected with the negative pole (-) and elektrode connected with the positive pole (+) of the DC welding machine, so that the arc moves from the base material to the electrode and the electrode is in the collision of electrons with the result 2/3 The heat was hot electrode and the third is in the base material. This will result in melting of the electrode more so having shallower penetration welds, and both are used in welding thin plate with a weld bead width.

electrodes

Please also note the AWS classification of SMAW electrodes denoted by the composition of code as follows: With the information that: E: states electrode XX: optional code that indicates the material tensile strengthX: optional code that indicates the position of welding X: optional code that shows cellulose - the type of flow and the layer

Digit Type of Coating Welding Current

0 High cellulose sodium DC+1 High cellulose potassium AC, DC+ or DC-2 High titania sodium AC, DC-3 High titania potassium AC, DC+4 Iron powder, titania AC, DC+ or DC-5 Low hydrogen sodium DC+6 Low hydrogen potassium AC, DC+7 High iron oxide, iron powder AC, DC+ or DC-

8 Low hydrogen potassium, iron powder AC, DC+ or DC-

E 60 1 1

Electrode Tensile Strength Position

Type of Coating and

Current

Welding Joint

• Butt Joint• Lap Joint• T Joint

• Corner joint• Edge Joint

Butt Joint

A joint between two members aligned approximately in the same plane

Lap Joint

A joint between two overlapping members

T Joint

A joint between two members located approximately at right angles to each other

Corner Joint

A joint between two members located at right angles to each other

Edge Joint

A joint between the edges of two or more parallel or nearly parallel members

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