The general large-diameter seamless steel pipe production process can be divided into two types: cold-drawn and hot-rolled. The outer diameter of the hot-rolled seamless pipe is generally greater than 32mm and the wall thickness is 2.5-200mm. The outer diameter of the cold-rolled seamless steel pipe can be up to 6mm. The thickness can be up to 0.25mm, and the outer diameter of the thin-walled tube can be up to 5mm and the wall thickness is less than 0.25mm. Cold rolling has higher dimensional accuracy than hot rolling.

The production process of cold-rolled seamless steel pipes is generally more complicated than that of hot rolling. The billet must first be subjected to three-roll continuous rolling, and then the sizing test must be carried out after extrusion. If the surface does not respond to cracks, the round pipe must be cut by a cutting machine. Cut into blanks about one meter in length. Then enter the annealing process. Annealing should be pickled with acid 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 on the caliber.

The delivery state of hot-rolled seamless steel pipe 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, labeled, arranging specifications, and placed in the warehouse.

As a seamless pipe manufacturer, Huzhou Nanxun Yintuo Special Material Technology Co., Ltd. is committed to producing various types of seamless pipes such as super austenitic stainless steel seamless pipe and tube. Please consult us for more details.