How seamless steel pipes are produced

①Main production process of hot-rolled seamless steel pipe (main inspection process):

Tube billet preparation and inspection → tube billet heating → perforation → pipe rolling → steel pipe reheating → fixed (reduced) diameter → heat treatment  → finished pipe straightening → finishing → inspection (non-destructive, physical and chemical, bench inspection) → storage

②Main production process of cold rolled (drawn) seamless steel pipe:

Blank preparation → pickling and lubrication → cold rolling (drawing) → heat treatment → straightening → finishing → inspection

The production process of general seamless steel pipes can be divided into two types: cold-drawn and hot-rolled. The production process of cold-rolled seamless steel pipes is generally more complicated than that of hot-rolled. The billet must first undergo three-roll continuous rolling, and then it must be extruded. In the sizing test, if the surface does not respond to cracks, the pipe will be cut by a cutting machine and cut into a blank of about one meter in length. Then enter the annealing process, the annealing should be pickled with acidic liquid. When pickling, pay attention to whether there is a lot of blistering on the surface. If there is a lot of blistering, it means that the quality of the steel pipe does not meet the corresponding standards.

In appearance, cold-rolled seamless steel pipes are shorter than hot-rolled seamless steel pipes. The wall thickness of cold-rolled seamless steel pipes is generally smaller than that of hot-rolled seamless steel pipes, but the surface looks brighter than thick-walled seamless steel pipes. Much rough, without too many burrs.

The delivery state of hot-rolled seamless steel pipes is generally delivered after heat treatment in the hot-rolled state. After the quality inspection, the hot-rolled seamless steel pipes must be strictly hand-selected by the staff. After the quality inspection, the surface must be oiled, and then followed by multiple cold drawing experiments. After the hot-rolling treatment, the piercing experiment must be carried out. , If the perforation diameter is too large, straightening should be carried out. After straightening, it is transferred by the conveyor to the flaw detector for flaw detection experiment, and finally the label is affixed, the specification is arranged, and then it is placed in the warehouse.