Pickling Line

Stainless Steel Annealing and Pickling Line

It is a coupled annealing and pickling process for processing stainless steel. The incoming hot rolled coil will be annealed for solution treatment and the cold rolled strip will be annealed to eliminate the machining hardness caused by cold rolling, then the strip will undergo pickling to remove scale and dirt caused by hot rolling and annealing, followed by passivation treatment to get corrosion proof behavior. For different stainless steel products, different annealing processes and different acid concentrations will be selected.

The line will be arranged with tension leveler, shot blasting machine, skinpass mill and paper backing machine, etc. according to the required annual output and User’s requirements.

Main characteristics

  • Employment of advanced welder which can weld strips of different thickness with good welding quality to reduce strip breakage ratio and improve line productivity;
  • Usage of descaler and shot blasting machine to descale the strip before pickling by combined wet type descaling and water spraying technology for removing dust or scale on the surface of strip and machine and ensuring desirable descaling effect in the workshop;
  • Installation of high efficient horizontal annealing furnace of tunnel type where the strip is annealed by using natural gas, and preheated by using waste gas to reduce energy consumption;
  • Selection of advanced heating and cooling process which can operate at desirable heating and cooling curve, resulting in less oxidization of strip inside the furnace and higher product yield;
  • Treatment of acid bearing waste gas by SCR process to change NOX in waste to N2 and H2O, allowing the exhausted gas reaching the National standard on waste gas emission;
  • Recovery of free acid in the waste acid liquid by ion exchange technology to reduce acid consumption and save production cost.

Technical data

Raw material: hot/cold rolled stainless steel such as series 200, 300, 400, DP, precipitation hardened steel, etc.

Final product size: 800~1600mm× (hot rolled 2.0~12) mm or (cold rolled 0.3~3.0) mm

Process speed: max.80~100m/min

Annual output: 400,000~500,000 t/a (hot rolled stainless steel) or 200,000~250,000 t/a(cold rolled stainless steel)