Seamless Steel Pipe Production Process: The Difference Between Cold Drawing And Hot Rolling

Exploring the production process of seamless steel pipes, we found significant differences between cold drawing (rolling) and hot rolling (extrusion). Although the first three steps of these two methods are similar, the real difference starts from the fourth step.

Firstly, after the round billet is punched, the cold drawn seamless tube needs to undergo heading and annealing treatment. After annealing, acid washing with acidic liquid is crucial. After pickling, the steel pipe will be coated with a layer of oil to prevent oxidation.

Next, the steel pipe will undergo multiple cold drawing (cold rolling) processes, followed by specialised heat treatment. After heat treatment, the steel pipe will be straightened to ensure its straightness and accuracy.

In contrast, the production process of hot-rolled seamless steel pipes is slightly different. Although there are also steps such as punching, heading, and annealing, the hot rolling process relies more on high temperature and pressure to form, rather than cold drawing or rolling.

Whether cold drawn or hot rolled, the production of seamless steel pipes is a complex and precise process, and each step is crucial to ensure the quality and performance of the final product.