Welding process (welding) is one of the splicing process material (material joining). As for the definition of the welding process which refers to the AWS (American Welding Society), the welding process is the process of switching between metal or non-metal that produces an integral part, by heating the material to be connected to the specific welding temperature, with or without suppression , and with or without filler metal. Although the method of the welding process is not only a process of grafting, but can also be a process of cutting and brazing. Welding process can be divided into several types, and SMAW welding process is one that is commonly used, especially in the short welding in production, maintenance and repair, and for the construction field.
SMAW (Shielded Metal Arc Welding) is a welding process to melt the base material that uses heat from the electricity between the metal cover (electrode). SMAW is a manual work with the equipment includes a power source, wiring electrodes (electrode cable), cable work (work cable), 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, connection workpiece, the workpiece (weldment), and welding electrodes. One of the two wires from the power source attached to the work, the rest is attached to the electrode holder.
As in the AWS (American Welding Society), the principles of SMAW is to use heat from the arc to melt the base metal and the tip of a consumable electrode covered with a voltage of 23-45 volts of electricity used, and the use of electrical current to melt up to 500 amperes are commonly used ranged between 80-200 amperes. Where in SMAW process of oxidation can occur, this needs to be prevented because of the oxidation of metal is a compound that has no mechanical strength. As to prevent that the material is protected by a layer of adders welding protective substance called flux or melting slag take when welding. But because its density is lighter than the metal melted, the liquid flux will float in the liquid metal, and isolate the metal so it will not oxidize with the air outside. When frozen, the flux will also freeze and still protect the metal from oxidation.
In welding with the SMAW method, welding begins when an electric arc struck by making contact between the tip electrode and the work system. Intense heat melt the tip electrode arc and the work surface near the bow. Small bubbles of molten metal quickly formed at the end of the electrode, and then transferred through the arc stream into the molten weld pool. In this way, as the filler metal deposited electrodes are consumed. According to the length of the arc driven work systems and speed, melting and fusing some of the metal base and keep adding filler metal. When the arc to heat sources with temperatures above 9000 ° F (5000 ° C), the melting of the base metals occurs almost instantaneously. If welding is done either in the flat or horizontal position, the metal transfer is caused by gravity, the expansion of the gas, electric and electromagnetic forces, and surface tension. While on the other welding positions, gravity works against another force.
SMAW welding process with methods distinguished by the type of the current include AC and DC, where the DC current distinguished on DCEN (straight polarity direct-polarity) and DCEP (reverse polarity - polarity reversed). The difference between the current SMAW AC and DC are as follows:
For AC (Alternating Current) voltage drop on the cable does not much influence, less suitable for the weak currents, not all types of electrodes can be used, starting arc is more difficult, especially for small electrode diameter, the pole can not be exchanged, not a bow arc problems.
While the current DC (Direct Current) voltage drop is sensitive to cable length as short as possible, it can be used for small stream with a small electrode diameter, all kinds of electrodes can be used, arc starting easier, especially for small currents, the pole can be interchangeable, arc bow sensitive at the end, angle or part that many indentation.
Further to DCEN (Straight Polarity), the basic material or material to be welded is connected with the positive pole (+) and negative poles electrode connected to (-) on the DC welding machine. In this way arc moves from the electrode to the base material so that collisions of electrons in the material basis of the result 2/3 heat in the base material and the third heat in the electrode. This method will result in melting of the base material so that more than electrode welds have deep penetration, so both are used in welding a slow, small areas and for thick plates.
In DCEP (Reversed Polarity), basic materials connected with the negative pole (-) and electrode connected to the positive pole (+) of DC welding machine, so that the arc moves from the base to the electrode material and electrode electron impact resulting in 2/3 electrodes and the heat was on third heat in the base material. This method will produce more so that the melting electrode welds have shallow penetration, and both are used in welding thin plate with a width of weld bead.
SMAW (Shielded Metal Arc Welding) is a welding process to melt the base material that uses heat from the electricity between the metal cover (electrode). SMAW is a manual work with the equipment includes a power source, wiring electrodes (electrode cable), cable work (work cable), 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, connection workpiece, the workpiece (weldment), and welding electrodes. One of the two wires from the power source attached to the work, the rest is attached to the electrode holder.
As in the AWS (American Welding Society), the principles of SMAW is to use heat from the arc to melt the base metal and the tip of a consumable electrode covered with a voltage of 23-45 volts of electricity used, and the use of electrical current to melt up to 500 amperes are commonly used ranged between 80-200 amperes. Where in SMAW process of oxidation can occur, this needs to be prevented because of the oxidation of metal is a compound that has no mechanical strength. As to prevent that the material is protected by a layer of adders welding protective substance called flux or melting slag take when welding. But because its density is lighter than the metal melted, the liquid flux will float in the liquid metal, and isolate the metal so it will not oxidize with the air outside. When frozen, the flux will also freeze and still protect the metal from oxidation.
In welding with the SMAW method, welding begins when an electric arc struck by making contact between the tip electrode and the work system. Intense heat melt the tip electrode arc and the work surface near the bow. Small bubbles of molten metal quickly formed at the end of the electrode, and then transferred through the arc stream into the molten weld pool. In this way, as the filler metal deposited electrodes are consumed. According to the length of the arc driven work systems and speed, melting and fusing some of the metal base and keep adding filler metal. When the arc to heat sources with temperatures above 9000 ° F (5000 ° C), the melting of the base metals occurs almost instantaneously. If welding is done either in the flat or horizontal position, the metal transfer is caused by gravity, the expansion of the gas, electric and electromagnetic forces, and surface tension. While on the other welding positions, gravity works against another force.
SMAW welding process with methods distinguished by the type of the current include AC and DC, where the DC current distinguished on DCEN (straight polarity direct-polarity) and DCEP (reverse polarity - polarity reversed). The difference between the current SMAW AC and DC are as follows:
For AC (Alternating Current) voltage drop on the cable does not much influence, less suitable for the weak currents, not all types of electrodes can be used, starting arc is more difficult, especially for small electrode diameter, the pole can not be exchanged, not a bow arc problems.
While the current DC (Direct Current) voltage drop is sensitive to cable length as short as possible, it can be used for small stream with a small electrode diameter, all kinds of electrodes can be used, arc starting easier, especially for small currents, the pole can be interchangeable, arc bow sensitive at the end, angle or part that many indentation.
Further to DCEN (Straight Polarity), the basic material or material to be welded is connected with the positive pole (+) and negative poles electrode connected to (-) on the DC welding machine. In this way arc moves from the electrode to the base material so that collisions of electrons in the material basis of the result 2/3 heat in the base material and the third heat in the electrode. This method will result in melting of the base material so that more than electrode welds have deep penetration, so both are used in welding a slow, small areas and for thick plates.
In DCEP (Reversed Polarity), basic materials connected with the negative pole (-) and electrode connected to the positive pole (+) of DC welding machine, so that the arc moves from the base to the electrode material and electrode electron impact resulting in 2/3 electrodes and the heat was on third heat in the base material. This method will produce more so that the melting electrode welds have shallow penetration, and both are used in welding thin plate with a width of weld bead.
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Tagged @ SMAW (Shielded Metal ARC Welding)
