The Arvedi ESP process produces hot strip in a combined, continuous and uninterrupted casting and rolling process. In this type of plant, the energy consumption and the associated costs are up to 45 percent lower than those of conventional casting and rolling processes. This also means a significant reduction of CO2 emissions. With a length of just 180 meters, the plants also have considerably more compact dimensions than conventional casting and rolling mills. A wide range of high-quality and ultra-thin steel grades can be produced with the endless cast-rolling process.
Based on proven technology the Arvedi ESP process operates successfully since 2009 at the steel works of Acciaieria Arvedi S.p.A. (Arvedi), Italy, and enables improved production of hot-rolled coils.
On the basis of the unique design features and configuration of an ESP plant, the continuous, endless rolling of high-quality strip is now possible for the first time. Due to the highly compact ESP line arrangement with a total length of only 180 meters combined with the direct linkage of the casting and rolling processes, lower investment and operating costs will be incurred in comparison with conventional thin-slab-casting and direct-rolling plants.
Thanks to endless rolling operations, strip can be produced with uniform and repeatable mechanical properties along the entire strip length, and yield losses are reduced to a minimum because head- and tail-end strip croppings are virtually eliminated. Another decisive advantage is that with continuous rolling operations, the roll gap and pressure adjustments are constant during the entire rolling process – resulting in a longer roll lifetime – as opposed to the discontinuous and wear-intensive rolling of discrete transfer bars.
ESP lines are ideal for installation in Mini Mills or in existing steel works where additional production capacities of up to approximately three million tons per year are required.
Main plant sections and features
- Casting of thin slabs in a straight mold at thicknesses of 90-110 mm
- Strand-thickness reduction with liquid core to 70-90 mm
- Further strand thickness reductions in the in-line high-reduction mill to intermediate strip with a thickness of 10–20 mm
- Induction heating to ensure correct temperature conditions for finishing rolling
- High pressure descaling
- Reduction to final strip thickness in a 5-stand continuous finishing mill
- Strip cooling with laminar-water-flow cooling system
- Strip cutting with a high-speed shear prior to coiling
The quality of Arvedi ESP steel products is, at the very least, equal to the quality of steel produced in a conventional hot-strip mill.
Considering the uniform and consistent mechanical properties of the steel to be produced in the Arvedi ESP endless rolling process, superior products are the result. The outstanding surface quality is demonstrated in cold rolling tests by European premium automotive sheet suppliers. Examples of products that can be manufactured from steel produced in an Arvedi ESP also include the more demanding requirements for automotive applications, and household appliances.
Reasons for investing
Due to the unique process features and plant configuration of Arvedi ESP technology a host of operational, product and cost benefits can be achieved.
- Lower Capex and Opex due to the compact layout. Reduced full turn-key investment leads to a faster pay-back period
Lowest operation costs
- Production of large quantities of thin gauges (0.8 mm and less) at minimized cobbles, since threading of the material into the final rolling stands is not required
- Improved yield due to elimination of cropping of strip head and tail ends
- Significant energy cost savings due to short line length (180 m) and the direct linkage of the casting and rolling processes
- High added-value products by full control and consistency of geometrical and metallurgical properties due to constant rolling conditions
- Economical production of hot-rolled thin strip, substituting many cold-rolled strip applications
- A highly flexible process with short time to market
The latest process control and automation solutions are standard in Arvedi ESP lines and cover the entire process route from slab casting, induction heating, hot rolling and strip cooling to coiling.
A complete range of technological packages in the casting section regulate the steel level in the mold, monitor friction values for break-out prevention, casting speed, temperature and cooling parameters, as well as the settings for strand-thickness reduction in the high-reduction mill.
In the induction heater, exact temperature control is ensured with respect to the steel grade, slab dimension, throughput speed and downstream requirements.
In the finishing mill section all vital rolling parameters are monitored and controlled, including speed control, profile and flatness control, roll adjustments, feedback loops and also deviances to acceptable tolerance values and rectification measures.
In the cooling section the application of laminar cooling combined with detailed metallurgical know-how allows different steel grades to be produced such as HSLA or multi-phase steel grades for demanding downstream applications.
Finally, a plant-wide quality-control system monitors all quality-relevant parameters and, when deviations occur, proposes adjustments to ensure that the desired product targets are met.
ESP is the proven technology to meet today’s requirements in producing ultra-thin steel products and high quality steel grades.