Large-diameter welded steel pipe processing methods

The processing of large-diameter welded steel pipes involves a variety of techniques, each suited to specific applications and material requirements. These methods are designed to ensure the production of high-quality, durable welded steel pipes that meet the demands of industries like construction, oil and gas, and infrastructure development. Below are the key processing methods used in the production of large-diameter welded steel pipes.

Rolling:
Rolling is a widely used process where a metal billet passes through the gap of rotating rollers. The compression from the rollers causes the material's cross-section to reduce while its length increases. This method is commonly used to produce large-diameter welded steel pipes, as well as steel pipe profiles, plates, and other shapes. Rolling can be further categorized into cold rolling and hot rolling, depending on the temperature of the material during the process. Hot rolling is particularly effective for large-diameter pipes, as it helps in achieving the desired thickness and strength.

Forging:
Forging is a pressure-processing technique that uses reciprocating impact force from a hammer or the continuous pressure of a press to shape the metal billet into the desired form. This method is especially useful for producing large-scale materials with significant cross-sectional sizes, such as open billets. Forging can be divided into free forging (where the billet is shaped freely without a mold) and die forging (where the billet is shaped within a die). It is commonly used for materials that require high strength and durability.

Drawing:
Drawing is a cold-working process in which a metal billet, profile, or pipe is drawn through a die hole to reduce its cross-section and increase its length. This method is mainly used for cold processing and is often applied to refine the dimensions of pipes and profiles. It is especially useful for producing small to medium-sized welded steel pipes with precise dimensional control and smooth surface finishes.

Extrusion:
In the extrusion process, metal is placed in a closed extrusion cylinder, and pressure is applied at one end. The metal is then squeezed through a die hole, taking on the shape and size of the die. This method is particularly suited for the production of large-diameter welded steel pipes made from non-ferrous metals. It allows for the creation of pipes with complex shapes and high material strength. Extrusion is commonly used for pipes that require uniform thickness and smooth internal surfaces.

These processing methods enable manufacturers to produce large-diameter welded steel pipes with the desired mechanical properties, surface finish, and dimensions needed for various industrial applications. The selection of the appropriate method depends on factors like the material type, desired pipe size, wall thickness, and end-use requirements.