SAW Steel Pipe vs ERW Steel Pipe

SAW steel pipe (submerged arc welded steel pipe) can be divided into longitudinally seam submerged arc welded steel pipe (LSAW steel pipe) and spiral submerged arc welded steel pipe (SSAW steel pipe). Submerged arc welded pipe has the characteristics of high weld quality, high production efficiency, and smokeless arc ignition. Submerged arc welded pipe is widely used in pressure vessels, pipeline manufacturing, engineering beams, low-pressure fluid, and steel structure engineering.

ERW steel pipe is the abbreviation of electric resistance welded steel pipe. Electric resistance welded steel pipe has the characteristics of high efficiency, low cost, material saving, easy automation, etc., and is widely used in aviation, aerospace, energy, electronics, automobile, light industry and other industrial sectors.

This passage will talk about the difference between SAW steel pipe and ERW steel pipe.

SAW Steel Pipe vs ERW Steel Pipe

- Manufacturing Process

SAW is a manufacturing process that utilizes submerged arc welding of steel, which produces high current densities that prevent the flux layer from rapidly dissipating heat and concentrating on the weld area. ERW uses the skin effect and proximity effect of high-frequency current to heat and melt the edge of the pipe blank after the hot rolled coil is formed by a forming machine, and presses it under the action of a squeeze rollerwelding to achieve production.

- Surface Quality

The weld seam of ERW steel pipe is flat and smooth, which is better than that of submerged arc welding (LSAW, SSAW) steel pipe. Most submerged arc welded steel pipes are primarily internally and externally reinforced by welds.

- Weld Defect

There are fewer types of weld defects in ERW steel pipes than in SAW steel pipes. Due to the deposition of solvent in submerged arc welding, in addition to volume defects, more defects will be generated.

- Residual Stress Ratio

The residual stress of ERW steel pipe is lower than that of submerged arc welded steel pipe. Due to the sufficient deformation of the ERW welded pipe during the deformation process, coupled with the subsequent sizing of the flat ellipse, the vertical change of the ellipse, and the shrinkage, the residual stress of the ERW welded pipe becomes smaller.

- Overall Performance

Unlike SAW, ERW steel pipes can be scrapped and welded when the pipe develops a defect, which can lead to cracking or corrosion. So ERW welded pipe is more durable than submerged arc welded pipe.