1. The main production processes of hot-rolled seamless steel pipes (main inspection processes):

Preparation and Inspection of Tube Blank → Heating of Tube Blank → Perforation → Pipe Rolling → Steel Pipe Reheating → Diameter Determination (Reduction) → Heat Treatment → Finished Pipe Straightening → Finishing → Inspection (Non-Destructive, Physical and Chemical, Taiwan Inspection) → Warehousing.

2. The main production processes of cold-rolled (drawn) seamless steel pipes:

Blank Preparation→Pickling and Lubrication→Cold Rolling (drawing)→Heat Treatment→Straightening→Finishing→Inspection.

The general production process of seamless steel pipes can be divided into cold drawing and hot rolling. The production process of cold-rolled seamless steel pipes is generally more complicated than hot-rolled. First, the tube blank is subjected to three-roll rolling, and then a sizing test is performed after extrusion. If there are no cracks on the surface, the round pipe will be cut by a cutting machine and cut into a blank of about one meter in length. Then, we begin the annealing process, which requires pickling with acidic liquid. When pickling, pay attention to whether there is bubbling on the surface. If a large amount of blistering occurs, the quality of the steel pipe cannot meet the corresponding standards. In appearance, cold-rolled seamless steel pipes are shorter than hot-rolled seamless steel pipes, and the wall thickness of cold-rolled seamless steel pipes is generally smaller than that of hot-rolled seamless steel pipes. But its surface looks brighter, the surface is not too rough, and the caliber does not have too many burrs.

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