Arvedi ESP: The Best Strip Production Knows No Limits

Arvedi Endless Strip Production (ESP) technology has emerged as a game-changer in hot-rolled coil production, offering a highly cost-effective and innovative method for producing high-quality steel strip. With over three decades of experience, Primetals Technologies has continuously refined this technology, setting new benchmarks in endless casting and rolling.

Arvedi ESP technology produces endless hot-rolled coils (eHRC) from liquid steel in just 5 minutes through a seamless, continuous process. The line begins with the high mass-flow casting of a thin or medium-thick strand, which is immediately rolled to a transfer bar in a high-reduction mill. The method capitalizes on the cast strand's inverse temperature profile and hot core, requiring only a short inductive heater. This saves energy, reduces emissions, lowers rolling forces, and ensures optimal entry conditions for finishing rolling. Afterward, the strip is rolled to the final thickness in the finishing mill, followed by laminar cooling. A High-speed shear immediately cuts the strip before coiling.

Arvedi ESP is the only process with zero greenhouse gas emissions during casting and rolling. Since 2009, Arvedi ESP lines have produced far more than 100 million tonnes of green steel with zero direct CO₂ emissions, resulting in a total reduction of more than 30 million tonnes of CO₂ compared to traditional casting and rolling processes.

Thanks to the absence of tunnel furnaces, Arvedi ESP ensures the most compact layout among any other thin slab casting and rolling technologies, resulting in CAPEX savings, energy efficiency, and superior product quality due to reduced scale formation.

Nowadays, Arvedi ESP plants produce with a mass flow at around 8 t/min, which extrapolates into 3.3 mtpy. With the target of producing around 4 Mtpa on one strand soon, we work to ensure a gradual and realistic increase in the mass flow, while maintaining stable plant operation and the highest quality requirements.

Arvedi ESP has the most sophisticated emergency concept with the highest reliability. In the case of downstream stoppages, there is no need to send back full ladles or stop the sequence. Production can automatically switch to plate mode and select other products from the order book for further endless operation.​

Benefits of Arvedi ESP from Primetals Technologies

• Endless hot rolled coils (eHRC) offer endless benefits for thin and thick strips
• Zero direct greenhouse gas emissions during casting and rolling
• Complete flexibility in casting and direct hot rolling
• Profit-oriented production of endless hot-rolled coils
• Proven operational stability in endless mode

Endless Hot Rolled Coils Offer Endless Benefits for Both Thin and Thick Strips

• Uniform mechanical and geometrical properties from coil head to tail
• Highest Surface Quality of Hot Rolled Coils
• Hot rolled coils from ultra-light to heavy gauges
• Endless Hot Rolled Coils (eHRC) can be used as a Direct Application Product

Uniform Mechanical and Geometrical Properties from Coil Head to Tail

What makes endless Hot Rolled Coils stand out: Thanks to the stable production conditions, the endless produced material offers unprecedented uniformity and geometrical tolerances from coil head to tail. These factors become significant in terms of the yield for eHRC customers, as side trimming becomes obsolete and even decisive when stacking the material, e.g., for silicon steel’s application.

Highest Surface Quality of Hot Rolled Coils from Ultra-Light to Heavy Gauges

The Endless Strip Production (ESP) process delivers outstanding surface quality. The clean surface after the caster, thanks to the stable mold level, is then preserved by descaling ahead of the finishing mill, oxidation prevention between mill stands, and the continuously maintained condition of the work rolls. If special grades that require ultra-high surface quality are produced, a retractable descaler can be installed in front of the high-reduction mill.

Arvedi ESP is the only process that reached 0.6 mm thickness on a hot rolled coil—this is a world record. It covers the full range from ultra-light gauges to heavy gauges up to 25.4 mm (one inch).

Endless Hot Rolled Coils (eHRC) Used as a Direct Application Product

Since the Endless Strip Production (ESP) process meets the end product thicknesses for an extensive range of markets, the eHRC can be used as a direct application product, competing in the cold rolled strip market with incomparably low production costs due to the reduced number of production steps (omitting cold rolling and obligatory annealing). Arvedi ESP can partially substitute cold rolling, and Endless Strip Production material can also be used directly for end products. The uniform material properties of the eHRC make cold rolling and processing much easier, since there are no fluctuations within the incoming parameters. The reductions in cold rolling can be set to a minimum since the incoming eHRC gauges are smaller.

Endless Hot Rolled Coils (eHRCs) allow for higher sales margins, compared to conventional hot rolled coils, due to the price premium for better quality and the extended possibility of direct application. Additionally, downstream processors are willing to pay premium prices due to the easier processing of the uniform strip.

The Fully Green Solution from Liquid Steel to endless Hot Rolled Coil

• Zero direct greenhouse gas emissions during casting and rolling
• No gas-fired heating for hot rolled coil production required
• Lowest land footprint

Zero Direct Greenhouse Gas Emissions During Casting and Rolling

In a coupled casting and rolling process, temperature control throughout the whole line is of utmost importance. Arvedi ESP uses the energy of the hot strand for the first rolling step after casting. For the second rolling step, the most efficient way of flexibly adjusting the temperature is by using inductive heaters, which can easily be power-controlled and even turned on and off. Such inductive heaters consume electric energy only and do not create direct greenhouse gas emissions like other heating methods do.

No Energy-Consuming Tunnel Furnaces for Hot Rolled Coil Production are Required

Other plant concepts than Arvedi ESP use gas-fired or electrically heated tunnel furnaces, which are environmentally unfriendly and promote significant scale formation on the product surface. Additionally,  gas-fired furnaces cannot be flexibly controlled or switched off during idle times.

Lowest Land Footprint

Due to its compactness with lengths below 180 meters, Arvedi Endless Strip Production (ESP) stands for minimum temperature loss and an unbeatable low energy consumption. With its compact design, Endless Strip Production (ESP) saves up to 50 percent of length and, respectively, area compared to other thin-slab casting and rolling processes. Compared to conventional routes, ESP saves up to 80 percent of area in green steelmaking.

Complete flexibility in casting and direct hot rolling

• Endless hot rolled coils (eHRC) from commodity to advanced grades
• Steel grade, width, and gauge change
• Higher copper tolerance on scrap-based Electric Arc Furnace (EAF) routes

Endless Hot Rolled Coils from Commodity to Advanced Grades​

Arvedi ESP offers you everything from commodity and commercial segments to the most sophisticated applications. eHRC products are found in all steel grade families, from high formability to high strength. Arvedi ESP proves to be the perfect transition technology to change from hot strip mill product mixes to endless production.

Steel Grade, Width, and Gauge Change

During operation, Arvedi Endless Strip Production (ESP) offers you the following flexible options. Steel grade changes are handled fully automated in the tundish. Level 2 support is given by the Intermix Expert model. The width is controlled directly in the mold with the reliable DynaWidth hydraulic taper and width control. The stable conditions of endless rolling are crucial to the highest width accuracy. Thickness is controlled throughout the sequence by patented flying gauge changes, which omit off-gauge production during thickness changes in endless mode. Inline work roll change in the last finishing stands during ongoing hot rolling allows the highest sequence lengths without needing to hold a buffer, just as CO₂-emitting tunnel furnaces do.

Higher Copper Tolerance on Scrap-Based Electric Arc Furnace Routes

Due to its compact design, Endless Strip Production (ESP) can perfectly cope with higher amounts of tramp elements (such as copper) in a scrap-based electric arc furnace (EAF)production since there is little time for copper enrichment on the surface (no tunnel furnace) before the first rolling step. The steel on the Arvedi ESP line stays in the critical temperature range for selective oxidation for only 1 minute, while on the tunnel furnace TSCR (Thin Slab Casting and Rolling), it takes 15 to 30 minutes.

Profit-Oriented Production of endless Hot Rolled Coils

• Lowest Turnkey investment in steel production​
• Lowest conversion costs in steel rolling
• Double the work roll lifetime in hot rolling
• Endless Strip Production requires less alloying

Lowest Turnkey Investment in Steel Production​

As already mentioned above, Arvedi ESP saves up to 80% of the area used at conventional casting and rolling routes with its compact design. Besides the fact of less land consumption, Arvedi ESP drastically reduces Capital Expenditures (CAPEX), requiring minimal foundations, less steel structure, less cladding, less roofing, less piping, and less cabling.

Lowest Conversion Costs in Steel Rolling

Energy is saved through the compact design, using the heat of the hot strand for the first rolling step, and by efficient inductive heating, consuming energy only when the plant is actively casting and rolling.
Operational supplies are saved by drastically reduced maintenance at the extremely short inductive heater, as well as the doubled work roll lifetime due to endless operation. Yield is increased by avoiding head and tail losses in endless operation, and the short oxidation time in the compact layout leads to only a minimum surface scale. Personnel costs are reduced by operating only one strand and omitting slab storage operations. The dedicated, endless production line omits the compromises of other production modes like coil-to-coil, and its numerous advantages outweigh the pretended flexibility of multiple production modes.

Double the Work Roll Lifetime in Hot Rolling

Arvedi ESP has less work roll wear as the endless process avoids shocks and damages to work rolls from slab threading. As the first rolling step happens directly to the cast strand with soft core, the strip is perfectly formed at lower forces. In the finishing mill, wear-compensation work roll shifting in the final mill stands doubles the work roll lifetime, compared to other processes.

Endless Strip Production Requires Less Alloying

Thermomechanical rolling of HSLA or API grades requires staying below the non-recrystallization temperature, which is ensured by over-alloying. Contrary to this strategy, Arvedi ESP's stable, endless operation and high cooling rates by Ultra Early Power Cooling are advantageous to omitting such over-alloying. This allows for a reduction in necessary alloying elements like Nb, Ni, Cr, or Mo.