1. According to the welding process, the welding methods can be divided into: flat welding, overhead welding and vertical welding.
(1) Flat welding is divided into left welding method and right welding method;
A, the advantages of left welding method: the weld penetration is large, the weld can be seen clearly, and it is not easy to weld deviation; Disadvantages of left welding method: no molten pool can be seen. ?
B advantages of the right-hand welding method: the molten pool can be clearly seen, which is convenient for the formation and control of the weld. ? Disadvantages of right-hand welding method: the weld penetration is shallow, and welding deviation is easy to occur. ?
(2) Vertical welding is divided into downward welding and upward welding.
Flat welding is suitable for full range of current welding, while overhead welding and vertical welding are only suitable for low current welding. The length of the welding rod protruding from the contact is 10- 15 times of the diameter of the welding wire, and the welding angle is 45 degrees.
2. Three transitional states of welding:?
(1) short-circuit transition: that is, when welding with low current, the arc emits a steady "beep … beep ……" sound, and the sound is very continuous. At this time, the weld is beautiful and less spatter, which is suitable for thin plate welding.
(2) Droplet transition: For medium current welding, the current range is generally between 180 ~ 270A. At this time, the splash is slightly larger, and the arc has intermittent sound. This section is called "splash zone" in the welding process, and this splash zone has not been solved so far.
(3) Jet transition: also known as sub-jet transition, at this time, the splash is extremely small, the water flow is large, and the sound is "Si ...", and the weld is beautifully formed.
From the above points, we can know that short-circuit transfer welding and spray transfer welding should be considered emphatically, but droplet transfer welding can also be used in occasions with low requirements.
3. Pay attention to avoid welding defects. The main welding defects and their causes are as follows: