Stainless steel seamless pipe is hot rolled or cold drawn?

Stainless steel seamless pipe can be manufactured by hot rolling process, can also be manufactured by cold drawing process, which process depends on the use of the product, size requirements, performance requirements and production costs and other factors.

Hot rolled stainless steel seamless pipe

Manufacturing process: The hot-rolled stainless steel seamless pipe is generally produced on the automatic tube rolling unit. After inspection and removal of surface defects, the solid tube blank is cut into the required length, centered on the end face of the perforated end of the tube blank, and then sent to the heating furnace for heating. When perforating on the perforator, a cavity is gradually formed inside the tube blank, which is called the capillary. Then it is sent to the automatic tube rolling machine to continue rolling. Finally, the wall thickness of the whole machine is adjusted, and the diameter is determined by the sizing machine to meet the specifications.

Product features: The diameter range of hot rolled seamless steel pipe is large (such as 54 ~ 480mm), the wall thickness is also thicker (such as 4.5 ~ 45mm), and the pressure resistance and flexibility are good, and the process performance is excellent. En outre, the manufacturing cost of hot-rolled seamless steel pipe is relatively low, the production cycle is short, and the output is high.

Application: Hot-rolled seamless steel pipe is more used in the manufacture of structural parts and fluid transport pipelines with low strength requirements, but with good toughness, such as building structures, chaudières, water and gas pipelines, etc..

Cold drawn stainless steel seamless pipe

Manufacturing process: Cold-drawn seamless steel pipe is made by multiple drawing and annealing treatment. The concrete process is to pass the billet through the pass with a circular hole of a certain size, and gradually reduce the diameter of the pipe and increase the thickness of the pipe wall through multiple drawing. Before cold drawing, one end of the steel pipe should be headed (small caliber steel pipe) or welded (large caliber steel pipe) to prepare for the drawing process. After drawing, the steel pipe also needs to carry out bright annealing, demagnetization, pickling, straightening and other steps.

Product features: Cold-drawn seamless steel pipe is generally made of high carbon steel or alloy steel, with high strength, hardness and fatigue resistance, but the toughness is relatively poor. The diameter of cold-drawn seamless steel pipe is small (mostly below 127mm), the outer diameter accuracy is very high, the wall thickness is uniform, the dimensional accuracy is high, and the surface finish is good.

Application: Cold-drawn seamless steel pipe is mainly used in the manufacture of high precision, high pressure, high temperature and special media conveying pipes and mechanical parts, such as automobile drive shaft, turbine engine, high pressure container and so on. In extreme conditions, such as deep-sea oil and gas exploitation, aerospace and other fields, the long-term stability and corrosion resistance of cold-drawn seamless steel pipes have become irreplaceable advantages.

Sum up

Hot rolling and cold drawing are the two main processes for manufacturing stainless steel seamless pipes, which have advantages and disadvantages and are suitable for different application scenarios. When choosing which process to use for stainless steel seamless pipes, it is necessary to make comprehensive consideration according to specific needs and application scenarios.