Boosting Productivity and Quality in Slab Casting with ABB s Electromagnetic Systems

Size: px

Start display at page:

Download "Boosting Productivity and Quality in Slab Casting with ABB s Electromagnetic Systems"

Aleesha Rose
6 years ago
Views:

1 Boosting Productivity and Quality in Slab Casting with ABB s Electromagnetic Systems

Complete Range of Products for Slab Production Ladle Furnace Stirrer give: Clean steel

(no tuyeres) Reduced energy consumption Improved productivity FC Molds for medium/high-speed

Improved surface and internal quality Possibilities to increase productivity EMBR Rulers for

Possibility to enter new quality segments FC MEMS for medium/low-speed casting of conventional

Slab SEMS give: More isotropic magnetic properties for silicon steels Reduced ridging/roping

2 Complete Range of Products for Slab Production Ladle Furnace Stirrer give: Clean steel Improved yield of alloys Reliable stirring Reproducible quality Less rejects Improved safety (no tuyeres) Reduced energy consumption Improved productivity FC Molds for medium/high-speed casting of conventional slabs having individual control of the meniscus and penetration flow: Improved surface and internal quality Possibilities to increase productivity EMBR Rulers for thin slab casting: Improved surface quality Reduced mould copper wear Increased casting speed Possibility to enter new quality segments FC MEMS for medium/low-speed casting of conventional slabs: Direct control of meniscus flow Improved surface quality Reduced risk of mid-face crack Slab SEMS give: More isotropic magnetic properties for silicon steels Reduced ridging/roping for ferritic stain less steels and silicon steels Equiaxed structure with reduced centerline segregation

Reliable Partner with Unique Competence Long-term commitment in the Steel Industry Stirrers for slabs since

complete program Stirrers and brakes for every application Installed on more than 100 slab strands Innovative

independent control of the meniscus flow speed and narrow side penetration.

conventional slab casters The Strand EMS is placed behind rollers for optimum performance and reliability for

conductors giving: - Dry insulation with no wear from water particles or chemicals - Direct cooling gives low

worldwide Global network Local service Unique know-how in coil design Advanced transient 3-D computer

3 Reliable Partner with Unique Competence Long-term commitment in the Steel Industry Stirrers for slabs since the 1970s Vast metallurgical know-how Joint developments with leading steel companies Market leader with complete program Stirrers and brakes for every application Installed on more than 100 slab strands Innovative and unique products The FC Mold features outstanding performance for conventional slab casters with independent control of the meniscus flow speed and narrow side penetration. The EMBR Ruler enables thin slab casters to boost both quality and productivity FC MEMS for low/medium-speed conventional slab casters The Strand EMS is placed behind rollers for optimum performance and reliability for silicon steels and ferritic stainless steels Long life and minimum maintenance Rectangular hollow copper conductors giving: - Dry insulation with no wear from water particles or chemicals - Direct cooling gives low and even insulation temperature - Rigid windings with conductors molded into a solid block Local presence worldwide Global network Local service Unique know-how in coil design Advanced transient 3-D computer simulations of steel and inclusion flow pattern with electro-magnetic fields in customer processes. Optimized design for maximum performance and minimum power consumption

Improved Process Economy for Conventional Slabs A unique feature of the FC Mold with two magnetic fields in the mold (to the right in the above picture) is that it independently optimizes the

The mold powder entrapments are then almost completely eliminated and excellent flotation of inclusions is simultaneously achieved, resulting in outstanding quality and productivity.

compared to AC Technology (stirrers) results in: - Much lower electrical power costs - Normal mold Cu plate thickness - Normal mold Cu plate quality - Electromagnetic MLCs can be used - No special

4 Improved Process Economy for Conventional Slabs A unique feature of the FC Mold with two magnetic fields in the mold (to the right in the above picture) is that it independently optimizes the meniscus flow speed and minimizes the penetration flow. The mold powder entrapments are then almost completely eliminated and excellent flotation of inclusions is simultaneously achieved, resulting in outstanding quality and productivity. 90 % reduction of reject ratio for ULC deep drawing qualities with FC Mold and increased casting speed up to 30% for certain grades and with the FC Mold at JFE, Japan FC Mold with DC Technology compared to AC Technology (stirrers) results in: - Much lower electrical power costs - Normal mold Cu plate thickness - Normal mold Cu plate quality - Electromagnetic MLCs can be used - No special know-how required Reject ratio (%) Casting Speed (m/min) Silicon steels without and with ABB SEMS This example shows the reject ratio versus casting speed, tested by means of ultrasonic inspection. With the FC Mold, it is evident that the casting speed can often be increased. The ABB Slab Strand Stirrer is used mainly for ferritic stainless steel and silicon steel for decreasing the ridging and roping as well as centerline segregation and halfway cracks.

Improved Process Economy for Thin Slabs tilesize tilesize = 5" = 30.05 ft Feets 0 11 5 4 1 2 18 0 18 1 2 6 2 19 surface top side FS 0 0 0 0 = 5" = 31.

1146 1202 1273 1322 1400 1442 1527 1563 1655 1683 1782 1803 1909 1923 2036 2043 2164 2164 2291 2284 2418 2404 2546 2524 2673 2644 2800 2765 2927 2885 3055 3005 3182 Remark: Inserted by TCP/IP BDE

5 Improved Process Economy for Thin Slabs tilesize tilesize = 5" = ft Feets surface top side FS = 5" = ft Feets surface top side FS 0 0 TS BS TS BS Remark: Inserted by TCP/IP BDE Server Remark: Inserted by TCP/IP BDE Server Without EMBR With EMBR A high casting speed leaves to high turbulence in the mold and more mold powder entrapments. Therefore, the EMBR gives considerably better results at higher casting speeds. The result is evaluated via an optical surface inspection system after the last stand (F7) in the hot rolling mill. (Thyssen, Germany, 4th European CC conf, 2002) Thin slab casting results in a higher total oxygen level than conventional slab casting. With EMBR this level can be lowered to that of conventional casting. More important is that the bigger and dangerous inclusions (>50 µm) are even more infrequent than for conventional casting. The smaller inclusions have been examined by means of metallographic evaluation and the bigger ones by the slime method. (Handan Iron & Steel, China, AISTech 2005) 90 % reduction of surface defects with EMBR due to the almost complete elimination of mold powder entrapments. An optical surface inspection system placed after the last stand in the hot rolling mill shows the upper side of coils. (Nucor Steel, Berkeley, USA, AISE 2001) Thin slab without EMBR Total O (ppm) < 50 µm inclusions (# / mm 2 ) > 50 µm inclusions (mg / 10 kg steel) Thin slab with EMBR Conventional slab Improved product quality New market segments Increased casting speed Less rejects Margin X Volume = Result Cost Less rejects Reduced scarfing and grinding Reduced mould wear

Boosting Productivity and Quality with Electromagnetic Systems Elanders, 0505 In metallurgical processing, the technology for stirring and braking the melt is important to ensure a higher

As the leading company in this area, ABB can provide advanced solutions for stirrers and brakes, but can also assist our customers worldwide with service and maintenance.

ABB is the Complete Supplier of Electromagnetic Systems for the Metals Industry.

6 Boosting Productivity and Quality with Electromagnetic Systems Elanders, 0505 In metallurgical processing, the technology for stirring and braking the melt is important to ensure a higher quality and productivity. The resulting benefits in terms of reproducible quality and profitable production have been repeatedly demonstrated, often with pay-back times less of than a year. As the leading company in this area, ABB can provide advanced solutions for stirrers and brakes, but can also assist our customers worldwide with service and maintenance. Combined with our metallurgical know-how, this makes ABB an ideal partner in the selection and installing of electromagnetic systems. ABB is the Complete Supplier of Electromagnetic Systems for the Metals Industry. AF-EMS LF-EMS EMBR FC Mold FC MEMS MEMS Dual MEMS Mod MEMS Slab SEMS EM Stabilizer for coating lines SEMS FEMS Aluminum EMS 3BSE ABB Automation Technologies AB Metallurgy Department SE Västeras, Sweden Phone Fax info.metallurgy@se.abb.com ABB Inc. 90 Consumers Drive Whitby, Ontario, Canada L1N 7L5 Phone Fax

Advances in Strip Surface Quality from Thin Slab Casters

International Scientific Colloquium Modelling for Electromagnetic Processing Hannover, March 24-26, 23 Advances in Strip Surface Quality from Thin Slab Casters H. Trippelsdorf, R. Marraccini, S. Kollberg