1. Hot rolling production process: steel pipe is mainly longitudinally deformed; large-scale continuous production; large batch, few varieties; diameter-thickness ratio within 40; maximum diameter: 720 units, 820 units are less.
2. Hot expansion production process: steel pipe is mainly radially deformed; flexible production method, easy to organize; small batch, multiple varieties, multiple specifications; diameter-thickness ratio above 50; maximum diameter 1500.
3. Cold drawing production process: steel pipe cold processing, longitudinal deformation to reduce wall thickness; multiple varieties, multiple specifications; diameter-thickness ratio above 50; maximum diameter 914.
Medium frequency hot expansion seamless steel pipe process
It is to heat the qualified finished steel pipe continuously and evenly from beginning to end under the condition of temperature control, speed control, and diameter change rate control, and expand the mother pipe through the built-in conical mandrel to form a larger diameter steel pipe by the movement of the hydraulic cylinder piston.
Characteristics of medium frequency hot expansion seamless steel pipe
(1) Medium frequency hot expansion seamless steel pipe is based on the principle of hot processing plastic deformation of steel. The finished steel pipe is used as the mother pipe. The temperature, speed, and diameter change rate are controlled during the expansion process
(2) From the force analysis of the deformation zone during medium frequency hot expansion, the metal in the deformation zone is under longitudinal and radial compression and circumferential tension, not unidirectional force
(3) The diameter change of medium frequency hot expansion is completed in one step, which can improve the accuracy
(4) The heating temperature of medium-frequency hot expansion is moderate continuous and uniform, and it is not easy to produce cracks
(5) The heating method of medium frequency hot expansion process is overall continuous heating, not local heating
Production process flow: mother pipe-inspection-lubricant application, selection of matching core rod-diameter expansion-heat treatment-physical and chemical inspection-straightening and finishing-inspection of internal and external surface quality and size-head cutting-ultrasonic flaw detection and eddy current-spraying-finished product storage.
Post time: May-08-2025