The manufacturing process of steel pipe production can be divided into four basic methods: cold drawing, cold rolling, hot rolling, and thermal expansion.
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 rolling. In the sizing test, if the surface does not respond to cracks, the round tube must be cut by a cutting machine and cut into a blank of about 1 meter in length. Then enter the annealing process. Annealing should be pickled with acid liquid. When pickling, pay attention to whether there is a large amount of blistering on the surface. If there is a large amount of blistering, it means that the quality of the steel pipe does not meet the response standard. 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 on the caliber.
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 pipe must be strictly hand-selected by the staff. After the quality inspection, the surface shall be oiled, and then followed by multiple cold drawing experiments. After the hot-rolling treatment, the piercing experiment shall be carried out. , If the perforation is too large, it must be straightened. After straightening, it is transferred by the conveyor to the flaw detector for flaw detection experiment. Finally, the label is affixed, the specification is arranged, and then it is placed in the warehouse.