Annealing and Pickling Line (APL) for Silicon Steel Strip
The hot rolled strips (NGO and GO) are initially side trimmed through a rotating turret trimmer, annealed in a continuous process to eliminate brittleness prior to cold rolling and to modify the microstructure.
Process following the Recrystallization Annealing are mainly the mechanical descaling and the Pickling to fully eliminate scale and Si oxide underneath the scale.
Overview
Tenova, with its over 40 years of experience, is the only company with the competence and knowledge, of the entire multi-stage thermal process chain, which is required for the production of grain-oriented electrical steel strip.
The hot rolled strips (NGO and GO) are initially side trimmed through a rotating turret trimmer,annealed in a continuous process to eliminate brittleness prior to cold rolling and to modify the microstructure. The annealing process is followed by a controlled cooling stage with a cooling rate, which may range from 5 to 80 K/s depending on the steel grade required. This process is usually carried out in a nitrogen atmosphere to protect the strip surface.
Process following the recrystallization Annealing are:
the Scale Breaking, or more frequently Hi Si grades a Shot Blasting section to partially eliminate the scale from the strip surface, a pre rinsing section to pre-heat and pre-wet the strip surface, the pickling and accurate rinsing section to fully eliminate scale and Si oxide underneath the scale.
All the mechanical equipment and strip preheaters designed to thread brittle strips especially before the Annealing Furnace.
Terminal Equipment and Process Section present specialties like:
Pay Off Reels provided with double expansion mandrels, compact Down cut Shears with lateral extraction for simplified blade maintenance
High precision Rotating Turret Side Trimmer-Scrap chopper unit
Low Inertia and low strip stress loopers; Pre Rinse section, operated with hot water for: residual scale powder removal, strip pre-heating Improving significantly the pickling efficiency.
High turbulence shallow pickling tanks Special multiple cascade rinsing section with controlled acidity for high surface quality Side trimmer with rotating turrets.
Si red ( Silica reduction plant) to continuously remove the excess of Si sludges from the recirculating tank through sedimentation and press filter; piping and heat exchanger washing plant for simplified maintenance.
Related Solutions
Europe
Wolfgang Eggert
General Manager Sales Heat Treatment of Steel Strip, Tenova LOI Thermprocess
China
Peizhong Wang
Director of Sales Tenova LOI Thermprocess, Tenova Technologies (Tianjin)
Modernization, Service & Spare Parts
Marc Reynaert
Head of Revamp & Modernization, Tenova LOI Thermprocess
