Tube Production
The production of cold drawn precision steel tubes starts with the pickling of the pre-material in a fully automatic, computerised tunnel pickling plant with 9 bathes. Following the tubes are rinsed, treated with phosphate and soap and dried with hot air in automatic cycles.
After this the pre-material will be pointed for the intake to the drawing tools. Tubes with bigger diameter and wall thickness are pointed hot, smaller ones are pointed cold.
The cold drawing can be done on 9 different drawing benches with 4 optional drawing techniques: drawing without mandrel, over bar, over mandrel bar and floating mandrel.
This process changes the material’s structure. Therefore it has to be annealed to generate a recrystallisation. The heat treatment processes are carried out in an inert atmosphere where the temperature is automatically controlled. The tubes can either be normalised, soft annealed or tempered.
Special tempering processes guarantee excellent material features also with unalloyed materials and are an alternative for the complex annealing process.
The tensions resulting from the drawing process lead to distortion of the tube. This requires the adjusting process after the drawing process or the heat treatment. The adjusting will be done on state-of-the-art computerised 6 and 10 roll adjusting facilities.
All tubes can be checked with the following test procedures:
- Eddy current
- Ultrasonic
- Material mix up check (at the adjusting lines)
- 100% outer diameter control with laser (at the adjusting lines)
Besides these test procedures additional quality features provided by the customer will be checked in modern labs the prodcution plant is equipped with.
Being a specialist not only in tube drawing but in tube processing the voestalpine Rotec offers the processing of the drawn and adusted tubes as continuative process if required.
In a range from 2.000 -18.000 mm the tubes can be cut to lengths. A NC controlled cutting facility guarantees lowest length tolerances.
Here you can finde more details of the cut-to-lengths business.
