
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.
Tenova, with its over 40 years of experience, is one of the company with the competence and knowledge, of the entire thermal process, which is required for the production of non-grain-oriented electrical 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. The next step is in-line coating with insulating varnishes of different qualities, then a drying process in a special drying furnace, which is generally fitted with a thermal afterburner. Waste heat from the process is efficiently utilized for strip cleaning and drying.
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. Special Roll coaters for NGO insulation coating with on-line coating control system (closed loop) and Insulating varnish preparation and recirculation systems.
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.
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 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.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.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.