1, hot rolled seamless pipe is generally produced on the automatic tube rolling unit. After checking and removing the surface defects, the solid tube blank is cut into the required length, centered on the perforated end face of the tube blank, and then sent to the heating furnace for heating, and perforated on the perforating machine. In the perforation at the same time continuously rotating and advancing, under the action of the roll and the head, the inside of the tube blank gradually formed a cavity, called the capillary. It is then sent to the automatic tube mill to continue rolling. Then the wall thickness of the whole machine is adjusted, and the diameter is determined by the sizing machine to meet the specification requirements. It is an advanced method to produce hot-rolled seamless steel pipe with continuous tube rolling unit.
2, if you want to obtain a smaller size and better quality seamless pipe, you should use cold rolling, cold drawing or a combination of the two methods. Cold rolling is usually carried out on a two-high mill, in which steel pipes are rolled in a ring pass consisting of a variable circular groove and a stationary conical head. Cold drawing is usually carried out on a single or double chain cold drawing machine of 0.5 ~ 100T.
3. The extrusion method is to place the heated tube blank in the closed extrusion cylinder, and the perforating rod moves with the extrusion rod to make the extrusion part extruded from the smaller die hole. This method can produce steel pipes with smaller diameters.
Many people have heard of 316 stainless steel seamless pipe, but how is the seamless steel pipe made? Today, Xiaobian will tell you about this problem, and hope to help you.
316 stainless steel seamless pipe is made of a very good round steel as the main material, and then the round steel is perforated, in the process of perforation, when the solid round steel becomes a hollow round steel, the principle of perforation is to use high temperature, the round steel is softened, and then the middle of the solid part is all removed, this time it becomes hollow. The round steel that becomes hollow is the seamless steel pipe that we see.
There are many ways to produce seamless pipes. According to the delivery requirements, the seamless steel pipe can be produced by hot rolling (about 80 ~ 90%) or cold rolling and cold drawing (about 10 ~ 20%). The billets of hot rolling pipes are round, square or polygon ingot, rolling billet or continuous casting tube billet, and the quality of tube billet has direct influence on the quality of pipe.
The production process of 316 stainless steel seamless pipe is different according to its different production methods:
1. Hot rolling (extrusion seamless steel pipe)
Round tube blank → heating → perforation → three-roll skew rolling, continuous rolling or extrusion → Stripping → sizing (or reducing) → Cooling → straightening → hydraulic test (or detection) → marking → storage 2. Cold-drawn (rolled) seamless steel pipe: round tube blank → heating → perforation → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → Blank tube → Heat treatment → straightening → hydraulic test (inspection) → marking → storage.
2. Cold-rolled (drawn) seamless steel pipe
Blank preparation → pickling lubrication → Cold rolling (drawing) → Heat treatment → straightening → finishing → inspection.
