The production of seamless tubes using the extrusion process requires the starting material to be heated evenly and precisely The starting material is steel and stainless steel of various alloys. These are typically fed into the process in the form of sawn billets.
For the preheating horizontal induction systems are used in which the billets are transported through the heating coils and heated from ambient temperature (20°C) to approx. 1,000°C in order to be punched in the subsequent process step.
The punched billets are heated in the vertical intermediate heating to approx. 1,200°C. In the event that the billets are not preheated and have already been drilled, the systems are designed accordingly so that from ambient temperature can be heated to 1,200°C.
After punching, also known as the expansion process, the billets are placed in the final-heating and heated to the target temperature. According to the extrusion process, the billets are removed from the parallel vertical stations and fed to the press.