Generally speaking, there are several key points to form a beautiful and firm weld pattern.
The hand should be stable and can not shake, which is directly related to whether the welding pattern is beautiful or not.
The time should be well controlled.
The thicker the steel plate, the longer the welding time can be, otherwise it is easy to be incompletely welded;
On the contrary, the thinner one can be passed by to prevent welding penetration.
The starting point welding and ending time should be consistent, so that the welded things will be firm and can bear greater weight.
In the welding process, when a weld seam is welded, if the arc is pulled off immediately at the end, an arc pit lower than the surface of the weldment will be formed.
If the crater is too deep, it is easy to cause stress concentration and cracks, so the residence time must be well controlled, and we also need to fill the crater at the end.
Weld bead connection (as shown in Fig below)
Tail end connection is the connection mode of first welding the tail joint of the weld bead, which is most used;
Head to head connection is the connection method of continuing the welding joint from the beginning of the first welding bead.
It is required to strike the arc slightly in front of the beginning of the welding bead, slightly lengthen the arc, pull the arc to the beginning and cover its end, and then move in the opposite direction after the beginning is welded flat. See the figure below.
Tail to tail connection means that the rear weld bead starts the arc from the other end of the interface to the end of the front weld bead.
The welding speed is slightly slower to fill the arc pit, and then weld a short section forward at a faster welding speed and extinguish the arc. See the figure below.
Head to tail connection is that the end of the post-weld bead is connected with the beginning of the pre-weld bead.
The high temperature at the end is used to repeatedly melt the beginning of the pre-weld bead, and the weld bead is welded flat and then finished quickly.
The essence of weld bead ending is how to generate arc at the end of the weld bead.
General closing methods are as follows:
(1) Circle ending method:
When the welding rod moves to the end of the weld, move in a circle until the arc pit is filled, and then pull off the arc. This method is applicable to the ending of a thick plate.
(2) Repeated arc breaking ending method:
When the welding rod moves to the end of the weld, repeatedly extinguish and strike the arc at the arc pit several times until the arc pit is filled.
This method is generally suitable for thin plate and high current welding, but it is not suitable for alkaline electrode because it is easy to produce pores.
(3) Back welding ending method:
Move the welding rod to the end of the weld, stop it, and change the angle of the welding rod to weld back for a short section. This method is suitable for alkaline electrode.