[Technology] ESP strip production line technology introduction

LMMGROUP ESP strip production line technology introduction

[Technology] ESP strip production line technology introduction

1.main production process

    1.1 process layout and main technical characteristics

微信图片 20171228094333 - [Technology] ESP strip production line technology introduction

The main process features:

  • Thicker slab thickness compared to conventional thin slabs
  • High speed, high output
  • The liquid core is depressed
  • High temperature roughing and slab special temperature distribution
  • Electromagnetic induction heating, flexible adjustment of the strip temperature
  • Full headless rolling

Economic production of ultra-thin broadband steel

  • Rolling length is short with low investment
  • Produce high-quality hot-rolled coil with uniform texture
  • Low energy consumption, low emissions and environmentally friendly

    1.2 Caster specifications and product outline

微信图片 20171228094408 - [Technology] ESP strip production line technology introduction微信图片 20171228094422 - [Technology] ESP strip production line technology introduction

        1.3 Production capacity accounting

微信图片 20171228094429 - [Technology] ESP strip production line technology introduction

         1.4  Yield rate accounting

Bills balance (1.8%)

  • Turnover (6t / per pour)
  • Oxidative burning (0.3%)
  • Head and tail cuts at the beginning and end of pouring (Arvedi, for example, about 0.45-0.8%)
  • ESP conversion rate refers to the chartered from the car until the final product, the production rate of this line ≥ 98.0%

微信图片 20171228094434 - [Technology] ESP strip production line technology introduction

    1.5 Rolling line temperature process

微信图片 20171228094439 - [Technology] ESP strip production line technology introduction

2.The main equipment parameters and equipment features

     2.1 Casting key parameter

  • Casting machine form: straight arc
  • Radius of arc: 5m
  • Metallurgical length: 20.14m (11 sectors)

Mold form: Funnel equipped with electromagnetic brake

Mold length: 1200mm

  • Mold width: 920 ~ 1640mm (mold exit)

Mold thickness: 90 / 110mm

  • Slab thickness: 70-90mm, 90-110mm (110 for parallel rollers)
  • Design speed: Max.7.0m / min (blank thickness of 80mm)
  • Steel flow: max.6.5t / min

     2.2  Rolling key parameters

微信图片 20171228094445 - [Technology] ESP strip production line technology introduction

       2.3  CCM caster

微信图片 20171228094450 - [Technology] ESP strip production line technology introduction

  • Thicker slab thickness compared to conventional thin slabs for higher stand-alone throughput
  • Designed to achieve a pull rate of 7.0 m / min, ensuring high throughput and rough rolling reverse temperature field
  • Large bag turntable with lower slag detection, to reduce the steel slag tundish molten steel pollution, improve the purity of molten steel
  • Equipped with intelligent mold and expert system, with dynamic widening and breakout forecasting functions to improve caster operation rate and production safety

微信图片 20171228094457 - [Technology] ESP strip production line technology introduction

Equipped with mold electromagnetic brake, improve the purity of molten steel, and appropriately increase the pulling speed

 bending section with liquid core pressure function, optimize the mold flow field, improve the internal quality of slab

 Fan section with light pressure function, reduce the center loose and center segregation, improve the internal quality of slab

 Secondary Cooling With dynamic water distribution function, real-time monitoring of online thermal history of slab, slab temperature control precision to meet the follow-up of the slab on the temperature requirements

        2.4 HRM heavy reduction roughing mill

微信图片 20171228094503 - [Technology] ESP strip production line technology introduction

  • Reverse temperature distribution, relatively high center temperature for better crown and wedge adjustment
  • Strip cores achieve better material properties compared to more densely packed with conventional rolling processes
  • Large reduction of the reverse temperature distribution pattern in the rolling mill area, which saves a lot of energy during the rolling process due to the high and softer strand core temperature

       2.5 Pendulum Shear& Pusher Piler

微信图片 20171228094510 - [Technology] ESP strip production line technology introduction

        2.5.1  Tilting shear

Shear range: 10-110mm thickness; Shear speed: maximum 0.5m / s;

The main function:

  • dummy bars and blank blanks cut (endless blanks, head and tail wedges);
  • Slab cut in semi-headless mode;
  • For finishing and roll change or finishing and follow-up racks, it is used for splitting of plates and slabs

Push the waste roller

The main function:

 Spindle bar installation and offline;

 Designed for fast off-line characteristics, flexible production and effective buffer for downstream processes;

2.6 Hub-cutter and strip lifting device

  • The main function:Sampling function
    • In semi-headless mode, when the billet speed exceeds the cut-off range, the billet is cut;
    • Empty the intermediate billet between the pendulum shears and the drum shears to provide space for the production of subsequent intermediate panels during downtime in the finishing and subsequent stands;

 Inductive Heater Furnace

微信图片 20171228094518 - [Technology] ESP strip production line technology introduction

  • 3MW * 12 group, the maximum temperature rise 300 ℃

Precise control of finishing inlet temperature provides a temperature basis for thin gauge rolling;

  • According to the finishing temperature appropriate closed-loop temperature control to meet the needs of finishing temperature;
  • Induction heating length of only 10m, the formation of small scale oxide, reducing metal loss;
  • No energy consumption during no-load and maintenance period to improve energy efficiency and reduce production energy consumption;

微信图片 20171228094523 - [Technology] ESP strip production line technology introduction

         2.8 Pinch Roll Descaler

微信图片 20171228094527 - [Technology] ESP strip production line technology introduction

Descaling pressure: 40Mpa

 Low flow, high pressure, can reduce the temperature of the intermediate billet;

 Clear the strip surface of the oxide scale;

 front and back with a pinch roller, sealing water, reducing the surface water billet, while preventing water vapor into the induction heating furnace;

2.9  Finishing Mill

微信图片 20171228094532 - [Technology] ESP strip production line technology introduction

  • Long travel hydraulic AGC, fast response, easy to change specifications for dynamic implementation;
  • Work roll positive bending system;
  • Dynamic shifting system with load;
  • Work roll dynamic cooling;
  • Low inertia quick response looper;
  • Rolling lubrication;

2.10 Laminar Cooling

微信图片 20171228094537 - [Technology] ESP strip production line technology introduction

  • With laminar cooling device with high water tank, the flow control valve is adopted for the header to precisely control the flow of the header, precisely control the cooling speed of the strip and effectively control the mechanical properties of the strip;
  • Different cooling strategies, front cooling, rear cooling, dual-phase steel cooling strategy;
  • Mechanical performance prediction model;

      2.1.1  High Speed Shear

微信图片 20171228094541 - [Technology] ESP strip production line technology introduction

  • Headless production mode, the thickness of 0.8-4mm strip sub-roll cutting;
  • High-speed flying shears equipped with pinch rollers before and after the fly to ensure the stability of the strip during the shearing process, while cutting and coiling before the construction and finishing and coiling pinch roller Zhang Zhang, to ensure the tension of the strip stable;

       2.1.2  Down Coile

微信图片 20171228094546 - [Technology] ESP strip production line technology introduction

  • Introduce the strip head into the coiler and build the strip to take up the strip;
  • The lower roller of the pinch roll is of a moving design, which is used as a shutter during winding and as a transitional roller conveyor when idle.
  • Four-roll system is used;
  • Pressure control and step control;
  • In order to facilitate the stability of the head wear belt, equipped with a pressure roller in the transition roller to prevent the strip head floating;

 

3.Product quality status

微信图片 20171228094551 - [Technology] ESP strip production line technology introduction微信图片 20171228094555 - [Technology] ESP strip production line technology introduction微信图片 20171228094600 - [Technology] ESP strip production line technology introduction

4. Production debugging

     4.1 Production Process

微信图片 20171228094604 - [Technology] ESP strip production line technology introduction

         4.2 Production mode

       1)  Headless production model: Production: 0.8-4.0mm strip

        Continuous casting slab continuous casting machine into the large amount of rolling mill, rolled to 8-20mm intermediate billets, heated by induction furnace 1100-1200 ℃ into the five finishing rolling, laminar cooling coiled. Throughout the process, the caster to the coiler directly connected with the strip, through the winch before the high-speed flying shear sub-volume. There is no frequent wear and throwing process in the production process.

       2) Semi headless / monoblock production mode: Production: 4.0-6.0mm strip

The continuous casting slab is cut by roll shearing or drum shearing after it is rolled by a large amount of reduction, and is finish-rolled, layer-cooled and coiled into rolls. Throughout the process, 75% of the time, continuous casting and reeling directly connected, each roll of tape need to wear and cast with steel.

            4.3  Rolling plan

微信图片 20171228094609 - [Technology] ESP strip production line technology introduction

Rolling plan scheduling principle

  • In accordance with the technical annex, the over thickness control is within the following range: Thickness span ratio <20% when thick to thin gauge is over, Thickness span ratio <30% when thin gauge to thick gauge is rolled over; System kilometers 150Km;
  • According to the technical requirements, the thickness of less than 4.0mm production specifications, the use of headless mode of production. Therefore, according to the principle of thickness transition, a 20% thickness span transition is adopted for thicker specifications, <15% thickness span transitions for intermediate specifications, and <10% thickness span transitions for thin specifications , So the demand for transition specifications larger.
  • According to the ESP production process, full width rolling is used in a single pour.
  • Continuous casting during the finishing roll, roughing produces a valuable mid-plate, and the mid-plate produces more.
  • Based on the SVAI commissioning plan, commissioning in a single (semi-headless) production mode early in the commissioning phase and progressive headless rolling. 0.8mmm specifications in the functional examination of the rolling.
  • Arvidi1.0mm 轧程:Rolling process

微信图片 20171228094614 - [Technology] ESP strip production line technology introduction

      4.4  Production organization

  • The mill’s production organization centers on the ESP headless steel production line and meets the requirements to the maximum in all regions according to ESP requirements;
  • ESP headless steel production line and converter with single furnace vs. stand-alone production mode;
  • The width of the sprue is kept constant with the use of equal-width rolling in a single sprue (3000 tons) of the ESP headless steel line;
  • The same type of steel can be mixed with water production, in order to ensure the stability of rolling in the rolling ≤ 1.5mm mixing is prohibited when the production;
  • Because of the endless rolling mode used by ESP in the production of ≤3.5mm thickness specification, the transitional specification is required according to the thickness specification.
  • Due to the rigid connection between continuous casting and rolling line due to the layout of ESP line, it is closely linked with steel making and iron making. If there is any abnormality in all links, the whole line will be discontinued. Therefore, the stability of ESP, steelmaking and ironmaking equipment , Organization and coordination have high requirements.

Leave a Reply

table,th,td{ border-collapse:collapse; border:1px solid black; }