Electric arc welding electrode is encased in one of the electrical arc welding electrode feed, the the which uses an electric arc as a source of heat. The heat That Occurs in electric arc occurring Between the electrode with the workpiece, melting the tip electrode (wire) welding employment and local bodies, then form an alloy, solidifies into welds (weld metal). Wrap (which serves as an electrode flux coating will burn in time process, and the gas Occurs That will protect the process to the influence of outside water. Fluid will wrap on the surface of the weld solidifies and floats called slag, the the which can then be cleaned easily.
WELDING MACHINE (WELDING MACHINE).
Requirements of the SMAW process is a continuous supply of the electric current (electric current), the number of ampere and voltage stability of the welding flame is quite good (Arc) will REMAIN intact.
Where electric power (electric power) obtained from the welding machine by type currents are issued 3 (three) types of machines namely:
a. Machine with direct current (DC).
b. Machine with an alternating current (AC)
c. Machine with a combination of the direct current (DC) and alternating
(AC)
Machine on direct current (DC) equipped with the changing nature of alternating current component (AC) into direct current (DC) is a generator, Because That Is the electric current used here not from the battery, but the emergency power generator.
Alternating current machines do not need to be equipped with a generator, a transformer, but enough. Electric characteristics 80-85% efficiency. For a combination of AC and DC machine is equipped with a transformer and rectifier, the rectifier is the which has a function to smooth the flow.
Selection of Welding Parameters
The length of the arc (Arc Length) is Considered to be either more or less the same with him. electrode is used. Magnitude of the voltage used for welding every position not the same. For example he was. electrode 3 mm - 6 mm, has a voltage of 20-30 volts in flat position, and this voltage will be reduced Between 2-5 volts at a position above the head. Voltage stability is greatly Determines the quality of welding and also stability through sound during welding. The amount can be heard also affect welding current, wherein the amount of electrical current depending on the welding of the material and size of welds, the geometry of the welding connection, and he's kind of electrode. core electrode. For welding in the weld area has high absorption capacity That Necessary heat and large electric currents may also need additional heat. Moderate for steel welding alloys, the the which can be easily hardened his HAZ region too fast cooling effect, cooling it to withstand these high heat input is given to a large welding current. Welding of metal alloys, in order to avoid burning the element should be used alloying elements welding current is as small as possible. Also on the hot weld cracking may occur, for example, in austenitic stainless steel weld the use of heat so it cultivated as small as possible must small. Welding speed of the welding current depends on the parent material, type of electrode, he. Core electrode, the geometry of the connection, the connection accuracy. Necessary in order to more higher welding currents can Quickly.
Electrical polarity affect the outcome of an electric arc. Electric Properties on the arc direct current (DC) will be more stable than the alternating current (AC). There are two types of polarity is the polarity of the straight, where the object of positive and negative working electrode (DCEN). Reverse polarity is the reverse polarity ie the opposite. Characteristics of metal removal Occurs by ejection, then this polarity mepunyai more results in the than welding with straight polarity (DCEN).
The length of the arc (Arc Length) is Considered to be either more or less the same with him. electrode is used. Magnitude of the voltage used for welding every position not the same. For example he was. electrode 3 mm - 6 mm, has a voltage of 20-30 volts in flat position, and this voltage will be reduced Between 2-5 volts at a position above the head. Voltage stability is greatly Determines the quality of welding and also stability through sound during welding. The amount can be heard also affect welding current, wherein the amount of electrical current depending on the welding of the material and size of welds, the geometry of the welding connection, and he's kind of electrode. core electrode. For welding in the weld area has high absorption capacity That Necessary heat and large electric currents may also need additional heat. Moderate for steel welding alloys, the the which can be easily hardened his HAZ region too fast cooling effect, cooling it to withstand these high heat input is given to a large welding current. Welding of metal alloys, in order to avoid burning the element should be used alloying elements welding current is as small as possible. Also on the hot weld cracking may occur, for example, in austenitic stainless steel weld the use of heat so it cultivated as small as possible must small. Welding speed of the welding current depends on the parent material, type of electrode, he. Core electrode, the geometry of the connection, the connection accuracy. Necessary in order to more higher welding currents can Quickly.
Electrical polarity affect the outcome of an electric arc. Electric Properties on the arc direct current (DC) will be more stable than the alternating current (AC). There are two types of polarity is the polarity of the straight, where the object of positive and negative working electrode (DCEN). Reverse polarity is the reverse polarity ie the opposite. Characteristics of metal removal Occurs by ejection, then this polarity mepunyai more results in the than welding with straight polarity (DCEN).
Welding Implementation
Ignition of the arc welding can be done by performing a brief relationship with the parent metal electrode tip, and then separate them again until a Certain distance as the length of the arc. Where the normal arc length Between the the which is 1.6 - 3.2 mm.
Electric arc outages done by removing the electrode from the parent material. to Produce a weld bead connecting the well can be performed as follows:
Before the electrodes should be kept away from the parent metal arc length reduced first, then the electrode was kept in a position to more adequately tilted.
Movement of Welding Electrode
There are different Airways to stimulate the (swinging) welding electrode, namely:
Welding Techniques for Groove Connection Type
Ignition of the arc welding can be done by performing a brief relationship with the parent metal electrode tip, and then separate them again until a Certain distance as the length of the arc. Where the normal arc length Between the the which is 1.6 - 3.2 mm.
Electric arc outages done by removing the electrode from the parent material. to Produce a weld bead connecting the well can be performed as follows:
Before the electrodes should be kept away from the parent metal arc length reduced first, then the electrode was kept in a position to more adequately tilted.
Movement of Welding Electrode
There are different Airways to stimulate the (swinging) welding electrode, namely:
- Electrode is driven by forward and backward, this method is one form of weaving methods.
- Other forms of weaving is to make a move like and a half months.
- Electrode That resembles a figure 8 motion.
- Electrode with a rotating motion.
- Electrode movement by forming hesitation.
Welding Techniques for Groove Connection Type
Flat position (1G)
It is recommended to use methods Such as figure 9 A and B. This can be done to kind of connection penetration on both sides, but can also be done on one side only penetration. Type a flat position (1G) in the implementation very easy. Pipe material may be applied on the road playing the pipes.
Horizontal position (2G
2G welding pipe welding positions are horizontal, upright position to the pipe and welding Carried horizontally around the pipe. Difficulty horizontal position welding is the weight of the liquid weld itself it will always be down. The angular position of the 2G pipe welding electrodes is 90 ยบ. The length of the electrode movement Between 1-2 times the diameter of the electrode. When too long can lead to lack of good quality weld. Arc length in
short as possible try ½ times the diameter of the welding electrode. For the welding of filling made with a circular motion and Attempted to burn well on both sides of the seam so as not to occur ACAT. This movement is repeated for the next replenishment.
Vertical position (3G)
3G position welding done on the plate material. 3G is Implemented on a vertical position and the electrode plate. Difficulty of welding is similar to the 2G position due to the gravitational force of the liquid electrode welding.
Pipe welding in 5G position welding can be Divided into up
and welding down. Welding up is usually performed on the pipe wall has a high thermal Because It requires a teal. Speed up the welding direction to the direction of welding is lower than down, so the heat input per unit area is higher than the 5G welding pipe welding down. The position placed on a fixed horizontal position and the welding done around the pipe. So That the welding
well, it is Necessary to weld studs (tack weld) on 5-8-11 and 2 o'clock position. Start welding at 5:30 to 12:00 hours through 6 hours and then Followed by the 5:30 o'clock position at 12:00 over 3 hours
Movement of the electrode to pass root position (weld root) is regular at a distance triangles ½ times the diameter of the electrode arc.
Welding down
Usually done on a thin pipe and oil pipelines and natural gas. The reason the use of welding down more lucrative dikarenakanlebih faster and more economical.
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