Steckel Mills: Specialized Solutions Based on Engineering Experience

Steckel mills occupy a unique niche in hot flat rolling. They offer a cost-effective solution for low to medium production volumes and are particularly suitable for a range of products, including carbon steels, stainless steels, and superalloys. These mills are highly configurable to meet both planned and future market requirements.

The strength of the Steckel mill lies in its cost-effective and flexible process. Production levels range from a modest 20,000 tons to 1,700,000 tons in a tandem configuration. It accommodates strip widths ranging from 450 to 2,100 mm and grades, including carbon steels and stainless steels, as well as lower-volume niche grades with high added value, such as superalloys and special steels.

Steckel Mills from Primetals Technologies Consists of

• Primary descaler
• Vertical edger (located according to the process)
• Roughing mill stand (requirement according to throughput)
• Rotary crop shear
• Pinch roll descaler
• Steckel mill stand with entry and exit coiler furnaces
• Laminar cooling system
• Fully hydraulic downcoiler
• Coil handling system

Steckel Mill Descaling System

The Steckel mill rolling process requires both scale removal and the prevention of scale reformation. Primetals Technologies provides descaling solutions that deliver industry-leading surface quality while utilizing sustainable and maintenance-friendly methods. An optimized header design and automatic height adjustment achieve the target impact pressure, thereby reducing both energy and water consumption. Variable-speed pump drives drastically reduce energy consumption and improve equipment longevity. An oxide suppression system manages scale control.

Steckel Mill Coiler Furnaces

The coiler furnace technology enables a single-stand reversing mill to produce strip in coil using a compact layout, designed explicitly by Primetals Technologies for each application. To enhance thermal stability, a two-stage guide directs the strip onto the coiler furnace drum slot. It closes the furnace bottom, improving heating efficiency and temperature uniformity while reducing energy consumption. Energy consumption is further reduced by a recuperation system that recovers heat from waste gases and uses pulse-fired burners, which operate only on demand to promote better temperature uniformity. A forced-air system manages the furnace atmosphere, and waste gases are discharged through the heat recovery system. Each furnace is equipped with a passive deflector roll to minimize tension variation in the strip, resulting in enhanced rolling stability.

Steckel Mill Stand

The Steckel mill is configured according to production requirements, ranging from a single mill stand operation to higher throughput solutions with a roughing mill and tandem finishing stands, allowing for future phased upgrades. To offset the reversing nature of the Steckel mill, the mill stand is equipped with the Primetals Technologies Mill Stabilizing Device (MSD), which significantly suppresses vibration at strip threading and tail-out during reverse rolling, thereby improving strip steering. The process automation system designed by Primetals Technologies ensures optimum performance of the Steckel mill process.

Vertical Edger

The vertical edger is strategically located either at the entry of the roughing mill or the entry of the Steckel mill, depending on process requirements. It utilizes fully hydraulic technology, providing ease of load control and maintenance.

Downcoiler

Primetals Technologies offers a range of downcoilers selected according to project requirements. The standard complete hydraulic machine meets most market demands, while the Power Coiler addresses the needs for thicker, wider, and high-strength products. This downcoiler utilizes four wrapper rolls to assist in forming the coil, ensuring tight wraps and high-quality coils across the entire hot-rolled product range, including the highest-strength pipeline steels.

Coil Handling System

Primetals Technologies offers standard coil handling solutions as well as systems specifically designed to meet unique requirements in terms of orientation, capacity, sampling, banding, marking, and storage locations. Systems include sampling equipment offered for a range of gauges, which provides for coil spring prevention for thicker gauges. Coil transportation is typically managed by walking beam conveyors, with onward coil transport via the Primetals Technologies Modular Car System (MCS) as required.