20# Carbon Hot Rolled Seamless Steel Pipe

Hot rolled seamless steel tubes are generally produced on automatic tube rolling units. The solid billet is inspected and cleared of surface defects, cut to the required length, centered on the pierced end face of the billet, and then sent to a heating furnace for heating and piercing on a piercing machine. In the piercing at the same time constantly rotating and forward, under the action of the roll and the top head, the internal cavity of the billet is gradually formed, known as the rough pipe. Then sent to the automatic rolling machine to continue rolling. Finally, the wall thickness is evened out by the equalizing machine, and the diameter is set by the sizing machine to meet the specifications. Utilizing continuous tube rolling unit to produce hot rolled seamless steel pipe is a more advanced method.

Hot rolled seamless steel pipe process mainly includes the following steps:

Heating: The billet is heated to a high temperature (usually 1100°C-1250°C) to make it soft for subsequent processing.

Piercing: A piercing machine is used to punch a hole in the center of the heated billet to form a tubular hollow billet.

Expansion: Further deformation of the perforated billet by extrusion or rolling to enlarge the inner and outer diameters.

Finishing: Straightening of tubes after cooling to ensure uniformity in outside diameter and wall thickness and to remove surface defects.

Heat treatment: Heat treatment is carried out as required to improve the mechanical properties of the pipe.

Inspection: Ensure the quality of the pipe meets the standard through various inspection methods, such as ultrasonic inspection and pressure test.

Surface treatment: Anti-corrosion treatment on the surface of steel pipe, such as painting or galvanizing.