Precision Pipe Supplier-GNEE

• The second mode of production: from the billet (plate, strip) first directly molded welded into a certain size pipe, and then cold-drawn or cold-rolled into a finished tube, commonly known as DOM welded steel pipe. The main processes are forming, welding, sizing, cold rolling or cold drawing (with or without mandrel), or continuous cold drawing (i.e., electric welding - cold drawing joint production line). Characteristics: scattered production processes, long process and production cycle, covers a large area, good dimensional accuracy of the product, internal and external surface finish, mechanical properties and metallurgical organization of good condition.
• The third mode of production: from the billet (plate, strip) first directly formed and welded into a certain size pipe, into the continuous size reduction machine for cold reduction into a finished tube. The main processes are forming, welding, continuous cold reduction. Characteristics: compact production process, concise process flow, high unit production efficiency, fast specification range change, suitable for the production of small diameter and thin-walled welded steel pipe.

But fine-drawn steel pipe has a unique advantage, because its surface is not easy to be oxidized, which is mainly composed of fine-drawn steel pipe raw materials are inseparable. Fine-drawing stainless steel pipe is relying on its surface to form a very thin and solid dense stable chromium-rich oxide film (protective film), to prevent oxygen atoms continue to penetrate, continue to oxidize, and obtain the ability to resist corrosion!