32 kinds of refractory materials required by steel mills and their requirements
Working layer coating material
Tundish immersion steel nozzle
21) Tundish stopper rod
Tundish long steel nozzle
Long steel nozzle washer
Tundish fire mud
Tundish caulking material
Tundish permanent layer castable 27) Semi-water-cooled refractory cover for refining furnace
Electrode ring for ladle refining furnace 29) Ceramic fiberboard
High-aluminum refractory bricks
Low cement castable
Steel mills, electric furnaces, converters, pouring ladles, refractory materials, refractory requirements
Realed product：Magnesia carbon brick
Working layer coating material: MgO, its specification reference value is ≥80%. The number of cycles used must be greater than 13 furnaces (≧910min), and the refractory material shall not collapse or explode during use, and the residual thickness of the working layer at the position of the tundish slag line when offline must be ≥30mm.
Block brick: The analysis item is Al2O3, and its specification value R≥75%. The number of cycles used must be greater than 13 furnaces, and there must be no cracking or floating of refractory materials during use.
Stabilizer: The analysis item is MgO, and its specification value is ≥80%. The number of cycles used must be greater than 13 furnaces, and there must be no cracking or floating of refractory materials during use.
Tundish immersion steel nozzle: the production of 200 and 300 series steel grades needs to reach 13 furnaces (inclusive), and the number of furnaces for the 400 series 3/4/5-foot steel grades needs to reach more than 6/7/8 furnaces (inclusive), respectively. No cracking or fracture of refractory materials shall occur during use.
Tundish stopper rod: the production of 200 and 300 series steel grades needs to reach 13 furnaces (inclusive), and the number of furnaces for the 400 series 3/4/5-foot steel grades needs to reach more than 6/7/8 furnaces (inclusive), respectively. During use, there shall be no fracture of refractory materials, uneven head erosion, etc.
Tundish long steel nozzle: the number of times used must be greater than 3.5, and no fractures or other conditions shall occur during use.
Long steel nozzle washers: No bonding (such as bonding with the drain outlet or bonding with the long steel nozzle bowl mouth, etc.) shall occur during use.
Tundish fire mud: The analysis item is Al2O3, and its standardized value is 91.5%≥R≥85%. The fire mud shall not clump or pulverize during the validity period, and during use, there shall be no poor adhesion (such as sinking during SEN installation and poor bonding between SEN and tundish bottom plate, etc.).
Tundish caulking material: The analysis item is Al2O3, and its standardized value is in the range of 76%≤R<86%. The separation of refractory aggregates from water shall not occur during use, and the actual use conditions must meet the continuous production of 13 furnaces for steelmaking.
Tundish permeable layer castable: the analysis item is Al2O3, and its specification value R≥80%. The number of cycles used must be greater than 300 furnaces, each for about 75 minutes, and the refractory material shall not collapse or explode during use.
Semi-water-cooled refractory cover for refining furnace: used for VOD vacuum smelting operations, the guaranteed number of cycles is 65. The thickness of the refractory material (greater than 270mm) and the distance of the opening in the center of the refractory cover (1200±10mm) must meet the requirements, and 304 stainless steel wire needs to be added inside the refractory material to increase the strength. The refractory material requires good compressive strength and reasonable thermal conductivity at room temperature and high temperature. Reference composition of refractory materials: Al2O3≧80%. The main raw material is high-alumina castable, 7.5 tons/set, and the estimated consumption of a single set of refractory materials is 2.75 cubic meters, with a reference density of 2.75 tons/cubic meter.
Electrode ring for ladle refining furnace: used for LF isolation electrode rod to protect the water-cooled center ring. The guaranteed number of times is 125 times. Composition: Al2O3≧85%, refractoriness≥1790, Cr2O3≥3.5%. The iron wire inside the refractory material is Cr19Ti stainless steel wire, specification: 0.1mm, ratio: weight accounts for 3%.
Ceramic fiberboard: Specification: 1100mm*700mm*50mm or 1100mm*700mm*80mm, composition inspection: element Al2O3≥35%, the maximum operating temperature is 1260℃, and the theoretical bulk density is 250kg/M3. The heating permanent line change is 1000℃×24h≤2.
High-aluminum refractory bricks: specification 230*114*65mm, inspection element Al2O3≥55%. Refractory temperature: 1770℃, compressive strength: 44.1Mpa, specific gravity: 2350-2700 (kg/m3).
Low cement castable: inspection element Al2O3≥65%, specification DGG-2, bulk density: ≥50MPa, flexural strength: 1350℃×3h≥6MPa, operating temperature: 1500℃, compressive strength: 1350℃×3h≥50MPa, packaging specifications: the outer packaging is packed in space bags, and the inner packaging is packed in moisture-proof packaging, 25kg/pack.
Refractory cotton: 7200*610*25mm or 7200*610*10mm, composition inspection: element Al2O3≥36%.