erw pipe raw material

Process of Creating ERW Steel Pipes

There are numerous manufacturing techniques to get industrial-grade pipes. The process of creating ERW steel pipes is among these techniques. ERW pipes present high strength and endurance for fluid transfer and other structural applications. 

ERW steel pipe is manufactured by rolling metal ERW pipe raw material, and then welding it longitudinally through its length.

What is ERW?

ERW signifies electric resistance welding and it is mainly used to define a particular technique in pipe manufacturing. In this method, two uncoiled rolls of steel sheets are connected without the demand for a welding filler wire or metal. 

In its place, the sheets are joined through the passing of an electrical current and a continuously applied force by the steel bars company.

The Manufacturing Process ERW Steel Pipes

  • Cold-forming: Cold-forming is a technique of functioning or forging a metal sample, steel – commonly in a room temperature setting. This indicates that the forging occurs below the steel’s recrystallization temperature, which helps eliminate the impurities from the material. 
  • When this happens, the grain structuring of steel is changed to become tinier and less coarse, hence giving rise to a hardened material with very trivial waste found in the machining procedure.
  • Passage of current: ERW pipe creation is a continuing process that occurs in a continually-moving machine. Though it happens so, the various stages that involve it can even be recognized and characterized. 
  • After the cold-forming procedure, there is a passing of electrical current between the ensuing edges of the cylindrical steel. Gradually, they are combined out of the current with the aid of an induction coil, and then placid pressure rolls to keep the cylindrical shaping.
  • Forming: Forming is another procedure that occurs in ERW manufacturing. The steel coils that traverse the ERW-creating machine, as stated before, cause cylindrical-shaped sheets that require to be welded through electrical current. 
  • To better explain this, the sheets first seem to be U-shape in appearance, that have numerous open welded joints, or edges, as they are known.
  • Welding: If you have ever come across seamless and non-seamless pipes before, then it is cool to recognize where the manufacturing techniques start to vary, once they are likened to ERW pipes. 
  • Seamless pipes may seem to be comparable in appearance to ERW pipes, but they utilize a non-contact electrical current. No welding happens in seamless pipes. 
  • Thus, it causes an endlessly smooth surface that has no noticeable edges or joints. Seamed pipes, in contrast, may utilize a welding filler, something that is not located in the ERW welding procedure.
  • Sizing and cutting: When the U-shaped joints are welded together, an ERW pipe can be dependent on post-processing methods to improve the properties of the material, along with its usability.


The procedure of creating ERW steel pipes is distinctive in that it utilizes an electrical current to weld the joints in position. In this method, rather than having to consume a welding filler to connect the edges, a non-contact induction coil is consumed with the aid of an impeder to converge the current to the limits of the pipe.

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