Mandrel for medium frequency thermal expansion: divided into guide zone, deformation zone, sizing zone, leveling zone and straightening zone

D1=D0-6;   D2=D0-2S0+0.3;   D3=D2-(3~5)

L1=300~500;   L3=200~300;   L4=300~400;

L5=2000~2500

Medium frequency thermal expansion seamless steel pipe process:

Under the condition of temperature control, speed control and diameter change rate control, the qualified finished steel pipe is heated continuously and uniformly through intermediate frequency from beginning to tail, and the master pipe can be passed by the movement of hydraulic cylinder piston.

The built-in tapered mandrel is expanded into a larger diameter steel pipe.

The characteristics of medium frequency thermal expansion seamless steel pipe:

The main results are as follows:

(1) the medium frequency hot expanded seamless steel pipe is based on the plastic deformation principle of hot working of iron and steel. The finished steel pipe is used as the master pipe, and the temperature, speed and diameter ratio are controlled in the process of diameter expansion.

(2) according to the force analysis of the deformation zone in the process of mid-frequency thermal expansion, the metal in the deformation zone is subjected to longitudinal and radial compression and circumferential tension, not one-way force.

(3) the variable diameter of intermediate frequency thermal expansion can be achieved in one step, which can improve the accuracy.

(4) the temperature of medium frequency thermal expansion heating is moderate and continuous, so it is not easy to crack.

(5) the heating mode of medium frequency thermal expansion process is whole continuous heating rather than local heating.

The advantages of our intermediate frequency thermal expansion:

(1) our company is equipped with 820 ultrasonic detection line and 100% ultrasonic inspection of finished products, which is safe and reliable and of excellent quality.

(2) flexible production, energy saving and environmental protection, convenient for small batch and multi-variety

(3) good internal and external surface quality and less oxide scale

(4) High dimensional accuracy and easy connection of pipe fittings

(5) the outer diameter of the steel pipe is large, and the outer diameter of the steel pipe can reach 914mm.

(6) the pipe wall is thin, and the diameter wall of Dhammer S is Prida 40,100.

(7) large outer diameter and long length, and the length of Φ 914mm steel pipe can reach more than 10m.

(8) the adaptability of steel grade is strong, and the steel tubes of all kinds of materials can be thermally expanded.