How to weld large gaps in vertical welding of galvanized square pipes?

This is Serena He, chief sales officer from Yishang.Today, we discuss how to solve the problem of large gaps when galvanized square pipes are vertically welded.

The butt welding method with gaps in galvanized square pipes, with a thickness of 1.2 millimeters, is very difficult to weld. Why? 

Because there is a zinc coating on the surface of galvanized pipes, the zinc coating on the surface of the pipes particularly affects the formation of welding seams.

If the welding method is not well mastered during welding, it is easy to weld through the gap.

There are two welding methods for welding square pipes with large gaps:

The first type: Do not adjust the welding current too high, and press the welding rod up bit by bit. The disadvantage of this method is that it is too slow and if the temperature of the molten pool is not well controlled, it can easily burn into holes.

Second type:

① You can find a suitable iron wire to place in the gap and press it up and weld it bit by bit. Adding iron wire welding can reduce the temperature of the weld pool and increase the filling amount of molten iron in the weld. The advantage of this method is that it can quickly weld upwards.

② If a suitable iron wire is not found, the coating on the welding rod can be knocked off as the iron wire, which is the most suitable method.

Welding method:

Method 1: We can choose welding rods with diameters of 2.5, 3.2, and 4.0 based on the size of the gap for welding. During the welding process, we can evenly weld the left and right points, which can make the weld seam fuse better.

Method 2: You can weld upwards by pressing a little in the middle. During spot welding, the welding rod should be slightly shaken to make the left and right fusion of the weld better.

Welding points:

When welding each arc, try to control the temperature of the molten pool as much as possible. Wait until the color of the previous arc's molten pool turns red and dark before proceeding to the next arc. It is important to control the rhythm, as if the rhythm is too fast, it can easily burn through the surface of the base metal. When welding, pay attention to the angle of the welding rod. The left and right angles of the welding rod are 90 degrees, and the downward inclination angle of the welding rod is 70 to 80 degrees.

Next, we will use acid j422 electrode with angular diameter of 2.5 and current of about 80 for trial welding. The following are the formed images after welding.

If you are interested in welding processing or have a project for welding, please share your ideas and requirements with us. 

We will provide you with a suitable solution. Contact us: huxanhe@zsyishang.com