Figure 1. General view of Foundry rolling unit of a new generation. 1. Continuous centrifugal casting machine; 2. Flying shears; 3. 10-stand finishing rolling block 170/150; 4. Hardening line; 5. Stacker of loop; 6. Conveyor with controlled cooling and compacting coils.
The main features of the new technology:
- The formation of the initial continuously cast ring ingot occurs in favorable conditions of a biaxial stress-strain state with a predominance of compression stresses. Favorable conditions are provided by the simultaneous action of the gravitational field arising from the rotation of the annular mold, and the “soft” reduction of the primary crusts of the solid phase by annular rollers in the area of expansion of the initial annular ingot to the required thickness of the billet.
- The cross-section of a rectangular billet as close as possible to the size of the finished rolled products. The thickness of the billet is in the range of 6 -: – 12 mm.
- The quality level of the billet for casting defects and the fine-crystalline structure of the primary crust of the solid phase provide high mechanical characteristics of the steel with a total draw of 4 -: – 6 units.
- The casting speed is in the range of 15 -: – 25 meters per second, which provides a direct combination of casting with rolling without preheating the rectangular billet before rolling.
- The rolling mill group consists only of a finishing 10 cage rolling unit with group drive.
- The weight of the riot is equal to the weight of the liquid metal in the steel-casting ladle and is 2.5 -: – 5.0 tons.
The table shows the technical characteristics of the Compact high-tech metallurgical complex for the production of wire rod in riots with an annual output of up to 50 thousand tons.
| № | Parameter name | Value |
|---|---|---|
| 1 | Product Range: Wire rod GOST30136-94 Rebar GOST5781-82, R2544-2006, № | 5,0;5,5;6,0;6,5;7;8;9;10;11;12 8;10; 12 |
| 2 | Weight of coil, tons | 2,5-:-5,0 |
| 3 | Productivity, thousand tons / year | 50,0 |
| 4 | Mode of operation, shifts | 3 |
| 5 | Annual fund of working time, hour | 6500 |
| № | Technical specifications | Value |
|---|---|---|
| 1 1.1 1.2 | Steel Department Induction steelmaking furnace, Number of melting units, pcs. Capacity of the melting unit for liquid steel, t Furnace hourly capacity, tons / hour The device loading the mixture into the furnace Capacity of the receiving container, m3 | 2 5 8,5 6,0 |
| 2 | Casting and rolling department Centrifugal injection molding machine The frequency of rotation of the ring mold, rev / sec Outer diameter of the ring mold, mm Rectangular blank width, mm Rectangular blank width, mm Casting speed, m / s Flying shears Cutting force, tons Drive power, KW Rolling mill type - continuous Finishing block of rolling stands Number of rolling stands, pcs Swath diameter, mm Group drive of the finishing block, KW Rolling speed at the exit, m / s | 2-:-5 1600 12-:-20 6-:-12 10-:-25 15 120 10 170/150 2500 до 120 м/сек |
| 3 | Rental cooling department Hardening line Coolant consumption, m3 / min Stacker of loop Conveyor with controlled cooling, length, m | 2,0-:-3,5 24,0 |
The considered new metallurgical technology allows to reduce capital costs per ton of production by 2.5 -: – 3.2 times. Unit capital costs are reduced to 210 -: – $ 250 / ton.
The reduction in specific capital expenditures was achieved due to:
- reduction of energy intensity and material consumption of technological equipment;
- reduction of production space per unit of output;
- the lack of unique steelmaking, steel-casting and rolling devices and mechanisms that require a high level of crane runways and high lifting capacity of cranes.
The considered metallurgical technology also allows to reduce production costs by 20 -: – 25%. Reduced production costs achieved by:
- use of the workpiece with dimensions as close as possible to the size of finished rolled products;
- exclude preheating of the original billet before rolling;
- the absence of excessive rolling strain during the formation of the finished profile;
- increasing the percentage of the dimension of rolled metal and yield to 0.985;
- reduction of the number of production personnel and support services.
Figure 2. Shows the layout of the production building of the compact High-tech metallurgical complex
