
Decarburizing and Coating Line (DCL) for Silicon Steel Strip
Cold rolled GO Si steel strip is annealed in a continuous process line for primary recrystallization and decarburization. After the steel strip has passed through the DCL furnace, it is coated with magnesium oxide and then dried.
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 final cold rolled GO silicon steel strip needs to be annealed in a continuous process line for primary recrystallization and decarburization to a level below 30 ppm. The decarburization of the silicon steel strip is necessary to make the steel ageing-resistant, so that the magnetic properties are stable even after long term operation as transformer core material. Besides the high requirement on accurate and reliable temperature profiles during annealing, soaking and cooling the atmosphere control in the DCL is essential.The atmosphere control, mixing and humidification system is the part with the highest degree of complexity in this annealing furnace.
The cleaning section is equipped with the special high-turbulence high-efficiency density (HTHE) electrolytic cleaning tank to enhance the strip cleaning. The strip is brushed with the high efficiency - quick maintenance brushing units of the brush-to-brush type.
Special steering rolls are able to improve the camber at furnace exit.Strip cooling sections before coating with multi-channels cooling rolls Special 3-roll coaters with hydrodynamic tray allow for the MgO insulation coating & adequate MgO slurry preparation system is designed with high shearing model.
Value for Money
- Key technology for the processing of silicon steel
- Highest process accuracy and repeatability guarantees stable magnetic properties
- Lower operational costs (electricity); lower investment and maintenance costs
- Top level coating uniformity with high cooling uniformity preventing material tensioning
Reference
- Worldwide reference installations at nearly all silicon steel producers
Digitalization
- Fully automated control system
- Various software modules for process optimization
- Improved strip camber and tracking along the line
Efficiency
- Modern heating technology
- Heat and energy recovery
Contact - List
Contact Contact Person Position Legal Entity Department Phone Fax E-mail Address LOI Thermprocess GmbH +49 201 1891-1 +49 201 1891-321 loi@tenova.com Am Lichtbogen 29
45141 Essen
Germany
Contact Contact Person Position Legal Entity Department Phone Fax E-mail Address General tenova@tenova.com Via Albareto 31
16153 Genova
Italy
Processing Lines for Silicon Steel
Annealing and Coating Line (ACL) for Silicon Steel Strip
Non-grain-oriented strip is annealed in a radiant tube furnace using a continuous process after cold rolling to ensure recrystallization and controlled grain growth. Top-quality steel requires strip temperatures above 1100°C and a very dry atmosphere with a high hydrogen content. This is followed by controlled cooling to obtain an extremely flat strip.Annealing and Pickling Line (APL) for Silicon Steel Strip
The hot rolled strips (NGO and GO) are initially 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.Flattening and Coating Line (FCL) for Silicon Steel Strip
For the final heat treatment process the transformer strip is coated with insulating varnish in an in-line process and then dried in an indirectly heated furnace. The steel strip is heated further in a radiant tube furnace with a controlled atmosphere and then straightened using the integrated hot stretching equipment. This stage is followed by a slow cooling process.Lamination Furnace for Semi-Finished Silicon Steel Strip
Semi-finished electrical steel requires an annealing process with recrystallizing, decarburizing and blueing. The punched laminations are continuously annealed in a roller hearth furnace or for smaller capacity in a pusher type furnace.