1. Annealing and Pickling Line (APL) for Stainless Steel Strip
  2. Annealing and Pickling Line (APL) for Stainless Steel Strip

Annealing and Pickling Line (APL) for Stainless Steel Strip

Tenova, with its over 40 years of experience, has the competence and knowledge of the thermal process which is required for the production of stainless steel strip.

The entry of an APL has a small sealing followed by a Preheating Furnace (PF). The strip is heated by waste gas coming from the Direct Fired Furnace (DFF), in the DFF strip is further heated to the required annealing temperatures and hold for certain soaking time. Strip is supported inside furnace by up-down rollers. After the annealing section, the strip enters a air cooling section followed by a water quench for final cooling and a wringer roller.

In recent years Tenova has addressed its research activities to develop new pickling technologies aimed at reducing both the polluting effects of the chemicals used and the overall process operational costs.

Eco4 (ECOcological and ECOnomical stainless steel pickling process) is a new stainless steel pickling process developed by Tenova which avoids formation of hexavalent chromium, reduces or eliminate completely NOx and nitrates in the waste water, reduces acid consumption, reduces overall energy consumption and reduces the investment and operating costs for spent acid and waste waters regeneration and treatment.

Pickling removes surface oxides and cleans surfaces to expose the bare metal. Pickling operations are very important in the manufacture of stainless steel and provide the transition between hot plant and cold plant, after the annealing operations. It involves multi-step chemical reactions, and is one of the most polluting and costly chemical processes in the steel industry due to the presence of the highly corrosive acids and hazardous substances such as hexavalent chromium and NOx.

This new process has not only a reduced environmental impact but also much lower operational costs thanks to a dramatic reduction of expensive acids (as HF and HNO3) used and, as a consequence, the energy and fuel consumption in the treatment of relevant wastes.

  • Value for Money

    Value for Money

    • Key technology for the processing of silicon steel
    • Highest process accuracy and repeatability guarantees stable magnetic properties
    • With Eco4: reduced electrical consumption, reduced acid consumption, reduced investment cost for fumes treatment and waste waters
  • Reference


    • Worldwide reference installations
  • Digitalization


    • Fully automated control system
    • Various software modules for process optimization
    • improved strip camber
    • accurate tracking and tension control along the line
  • Efficiency


    • Top quality pickled surface

Contact - List

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    Tenova LOI Thermprocess GmbH
    +49 203 80398-900
    +49 203 80398-901

    Schifferstrasse 80

    47059 Duisburg


  • ContactContact PersonPositionLegal EntityDepartmentPhoneFaxE-mailAddress

    Via Albareto 31

    16153 Genova