Welding method: When welding thick-walled steel pipes, first clean the oil, paint, water, rust, etc. from the welding joint, and then make a bevel according to the wall thickness. If it is thick, make it larger, and if it is thin, make it smaller (angle grinder), and then It is the gap between the products, which is generally 1-1.5 times the diameter of the welding rod or wire. If the groove is accidentally opened wider, it can be left smaller. There are at least three spots for spot welding, and generally, four spots work better. When welding, you should weld half and half, with the starting point about one centimeter beyond the bottom point, so that the joint can be made from the opposite side. If the steel pipe wall is thick, it should be layered, with at least two layers, and the second layer can be welded only after the entire circle of one layer has been welded.
Process flow: round tube blank → heating → perforation → three-roll cross rolling, continuous rolling or extrusion → tube removal → sizing (or diameter reduction) → cooling → straightening → hydraulic test (or flaw detection) → marking
Weld reinforcement: When the wall thickness of the steel pipe is not greater than 12.5mm, the weld reinforcement is not greater than 3.0mm; when the wall thickness of the steel pipe is greater than 12.5mm, the weld reinforcement is not greater than 3.5mm.
Curvature:
- Steel pipes with a nominal outer diameter of no more than 168.3mm should be straight or bent according to the bending index specified by the agreement between the supplier and the buyer;
- For steel pipes with a nominal outer diameter greater than 168.3mm, the bending degree shall not be greater than 0.2% of the total length of the steel pipe.
- For steel pipes with a pipe end wall thickness greater than 4mm, the pipe end can be processed with a bevel of 30°+5°0°, with a root of 1.6mm±0.8mm, and the pipe end slope is less than or equal to 5mm.
Post time: May-10-2024