A brief discussion on the characteristics of SSAW pipes

The SSAW pipe body has a longitudinal weld. When the diameter is greater than 914mm, two weldings are allowed. Welding wire is used for submerged arc welding.

Submerged arc longitudinal weld steel, referred to as ASWL, is a flux-protected weld; the biggest feature of submerged arc welded straight seam steel pipes is the use of external welding wire for arc heat melting and the use of submerged arc flux.
What is the difference between the production processes of high-frequency straight seam steel pipes and submerged arc welded straight seam steel pipes?
The production differences between high-frequency straight seam steel pipes and submerged arc welded straight seam steel pipes mainly lie in different raw materials, different forming processes, different welding processes, different production units, and different production scopes.
Submerged arc welded straight seam steel pipe is the narrowest 1250mm coiled pipe, and medium-thick plate and medium-thick plate are the raw materials for production. High-frequency straight seam steel pipes are made of strip steel with a maximum width of 1500mm. Strip steel costs less.
The forming process of submerged arc welded straight seam steel pipe is JCOE cold stamping, which is characterized by gradually forming the steel plate in units of 50mm. J, C, O and E represent the forming process of submerged arc welded straight seam steel pipe.

The high-frequency straight seam steel pipe forming process is a cold rolling forming process. In this cold bending forming process, both ends of the strip are squeezed by multiple rollers, and the ends of the strip are finally aligned. It is characterized by uninterrupted forming and continuous welding.
The characteristic of the submerged arc welding process is that the electric heating effect of the welding wire is used to fuse with the steel plate, which is filler welding. The characteristic of the high-frequency straight seam steel pipe welding process is that the high-frequency skin effect of the current is used to quickly heat up both ends of the strip in a short time, and the strip self-melts at high temperatures.
The high-frequency straight steel pipe production line is an uninterrupted production line with the same effect, while the submerged arc welded straight seam steel pipe has a complete set of intermittent production units that can carry out up to 15 processes.
High-frequency straight seam steel pipes have few specifications and thin thickness. Submerged arc welded straight seam steel pipes can be produced in any specification from 325 to 1600mm, with a maximum thickness of no more than 80mm.
How to distinguish between high frequency straight seam steel pipe and submerged arc welded straight seam steel pipe?
There are obvious differences in appearance between high-frequency straight seam steel pipes and submerged arc welded straight seam steel pipes, mainly in appearance and welds. From the appearance, the main body of the high-frequency steel pipe is smooth and has no oxide scale attached. In terms of welds, high-frequency straight seam steel pipe welds are extrusion, jagged and irregular welds. This weld is "scraped off" at the factory, leaving a relatively flat weld. Submerged arc welded straight seam steel pipes have slight band-like dents in appearance, which are mainly distributed inside the steel pipe. The neat height of the weld seam of submerged arc welded straight seam steel pipe is 1-3mm higher than that of the base material. The welds can be "polished" according to customer requirements before leaving the factory, and there will be clear grinding marks from the grinding wheel.