Knowledge

08Oct, 2024

Incomplete penetration and lack of fusion defects
During the welding process, there is a tendency for some parts of the steel plate and welding electrode not to melt into each other. This results in defects such as incomplete pene
08Oct, 2024

Solutions to Undercut Defects
The primary solution to undercut defects is to control the welding current well, which can largely avoid the occurrence of undercut defects. By maintaining a stable arc length and
08Oct, 2024

Causes of Undercut Defects
During the welding process, if a depression is formed at the edge of the weld, causing the weld seam to be lower than the base material, this depression is known as an undercut def
08Oct, 2024

Solutions to Slag Inclusion Defects
To improve the welding quality of spiral steel pipes and effectively address slag inclusion defects, it is crucial to properly handle the bevel dimensions. Determining the bevel di
08Oct, 2024

Causes of Slag Inclusion Defects
During the welding process, welding electrodes and steel plates generate certain amounts of slag, which cannot be completely removed. Some of this slag remains in the weld seam, ul
30Sep, 2024

Solutions to Porosity Defects
To better address porosity defects in spiral steel pipe welding, it is necessary to treat the weld surface based on the understood principles of porosity formation, which can effec
30Sep, 2024

Causes of Porosity Defects
During the welding of spiral steel pipes, gas voids can exist on or in the weld surface. This imperfection is known as porosity. The main reasons for porosity defects stem from ina
30Sep, 2024

What should be paid attention to during chamfering - Bevel and root face
Unless otherwise specified by the customer, steel pipes with wall thicknesses greater than 3.2mm should have a bevel of 30° to 35°; the root face should be 1.6±0.8mm
30Sep, 2024

What should be paid attention to during chamfering - Hard spots
The steel pipe must not have hard spots exceeding 50mm in any direction and with a hardness value higher than 35HRC (327HBW/345HV10). If any, they can be removed.
30Sep, 2024

What should be paid attention to during chamfering - Lamination and inclusion
When processing the pipe end, operators should carefully inspect whether there are laminations and inclusions in the pipe end. Steel pipes are not allowed to have laminations or in
27Sep, 2024

What is the role of chamfering?
After plasma flying cutting, the end face of spiral submerged arc welded pipe with double-sided welding may have defects such as uneven pipe ends, cutting obliquity, slag, and leng
27Sep, 2024

What is the role of repair welding?
Repair welding is required for steel pipes with defective welds or containing joint seams.

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