#Seamless Steel Pipe#Seamless steel pipes are widely used in many mechanical engineering fields, so how are they produced? Today, we will take you to understand the production method of seamless steel pipe.
1. Reducing rolling and sizing rolling.
Although there are no special technical developments, many large diameter fixed diameter machines also use three-roll fixed diameter machines. The disadvantage of using three rolls is that the roll gap cannot be changed, so there are many frames, but recently there is a variable roll gap mill, and the idea of a four-high pressure reducer is proposed. In the future, people will also pay attention to the direct connection technology of mandrel seamless rolling mill with fixed diameter machine and tension reduction diameter machine. The development of the above-mentioned high-alloy perforated mandrels in the field of steel pipes and the development of mandrel grooves and blank lubricants are closely related to friction technology to manufacture seamless steel pipes.
2. Stamping and rolling.
PPM (Pressure Roll Punching Machine) for square billets has been replaced by inclined roll punching machines for round billets. Conical punching machine with rotary forging effect, which can suppress circumferential shear deformation. Therefore, it can suppress defects on the inner surface of the steel pipe. It can be used for perforation of materials, especially hinges and thin walls. When using a common punch, the limit of wall thickness/outer diameter ratio (T/D) is about 6%, while when using a tapered punch, a thin-walled tube with a T/D of 3.2% can be punched.
3. Stretch straightening.
The mandrel seamless tube rolling mill has developed in the direction of large-scale and compact. The number of stands is reduced from 7 to 9 to 4 to 5, and the rolling energy consumption of the piercer and mandrel seamless steel pipe can be reduced by about 20%. In the control technology of the mandrel seamless pipe mill, in order to reduce the loss of the cutting head for the tension reduction in the pipe end wall thickness, the steel pipe mill adopts the oil pressure reducing device for the first time.
The so-called “one-piece” heat treatment forming in industrial production means that the axle body and axle head of the axle are made from a seamless steel pipe through heat treatment technology. Three-piece” axles require additional welding of the axle heads to the axle beams.
Post time: Jun-06-2022