Production process of seamless steel pipe and welded pipe

Stainless steel pipes are usually divided into two categories: seamless pipes and seam welded pipes. In the production process, the required equipment is also different. The difference can be seen from the production process flow chart of the two:

In the process of producing seamless pipes, piercing, cold drawing (cold rolling), and inspection are the key links in the entire process. Correspondingly, piercing machines, pipe drawing machines, pipe rolling mills and various testing equipment play a pivotal role in the entire production process.

Seamless steel pipe forming process

The more common ones include Φ50 , Φ90 , Φ250 series hot rolling piercing units. The Φ2000mm giant dragon piercing unit can pierce and roll solid billets with a diameter of 210-1000mm , and can also pierce and roll hollow tubes with a diameter of 1000-2000mm for a second time . The rolling specification of this unit is second to none in the world, which has greatly promoted the development of seamless steel pipe production equipment in China and the world and the progress of the giant-caliber seamless steel pipe market. Another TZC200 tapered roller piercing unit adopts a combined frame, tapered roller piercing, full hydraulic quick roll change and digital display numerical control feed angle adjustment technology, which is at the leading domestic level and reached the contemporary international level. It is used in some large domestic stainless steel plants.

OD508MM SCHXS Q345 20 meter spiral welded pipes

In the pipe forming process, cold drawing and cold rolling are two coexisting processes, and the effects achieved in actual production are the same, and the seamless pipes produced also have their own advantages. At present, among the stainless steel pipe manufacturing enterprises in China, the YLB100t , YLB150t , YLB250t , YLB550t series of high-precision hydraulic cold drawing units are the more commonly used cold-drawn pipe-making equipment with good reputation. Among the cold rolling mills, the LG30-H , LG55-H , LG60-H , LG60-2H , LG110-H , and LG250-H series of cold-rolled tube mills are the most widely used models. The LG-200 and φ159 tube rolling mills are also preferred units of some large steel mills. Among them, the LG-200 cold – rolling pipe mill can roll seamless steel pipes of φ125-200X3.5-22X4000-10000 specifications, and the φ159 continuous pipe mill can roll seamless steel pipes of φ114-159 pipe diameters.

The two parts of forming and welding are the main processes of turning the plate (strip) into a round tube. In the welding process, the most common types of welding equipment are straight seam high frequency welding equipment, straight seam double-sided welding process and spiral submerged arc welding process. The MU-25M , MU-32M , MU-57M , MU-76M , MU-159M , MU-325M series of automatic pipe welding units are also common equipment in welded pipe manufacturers.