Bearings Application in Metallurgical Equipment​

Metallurgical equipment operates under extreme conditions—high temperature, heavy load, severe dust, and frequent shock loads—posing stringent requirements on the performance of supporting components. Bearings, as core rotating parts, directly affect the stability, efficiency, and service life of metallurgical machinery. Below is a detailed breakdown of bearings’ application in key metallurgical equipment categories, along with technical demands and solution highlights.​

1. Application in Smelting Equipment​

Smelting equipment (e.g., blast furnaces, converters, electric arc furnaces) requires bearings to withstand continuous high temperatures (up to 200°C in some areas) and heavy radial/axial loads, while resisting corrosion from molten metal splashes and dust.

2. Application in Rolling Equipment​

Rolling mills (hot/cold rolling mills) and their auxiliary systems are the most bearing-intensive metallurgical equipment. Bearings here face cyclic heavy loads, rolling oil contamination, and thermal expansion of rolls.​

2.1 Key Application: Rolling Mill Rolls​

Rolls are the core components of rolling mills, and bearings must ensure their stable rotation under high pressure (up to several thousand tons of rolling force).​

Hot Rolling Mill Work Rolls: Spherical roller bearings (23000 series)​

Why: Excellent self-aligning performance compensates for roll bending caused by high temperature; enhanced load capacity handles cyclic radial loads.​

Special Design: Sealed structure with high-temperature grease (operating temperature ≤250°C) to prevent dust and rolling oil ingress.​

Cold Rolling Mill Backup Rolls: Tapered roller bearings (40000 series)​

Why: Combined radial-axial load capacity adapts to both rolling force and axial thrust from strip deviation; high rigidity ensures roll parallelism, improving strip flatness.​

2.2 Auxiliary Rolling Equipment​

Straightening Machines: Deep groove ball bearings (6200 series) with ceramic balls​

Advantage: Ceramic materials reduce friction and heat generation; resist wear from metal oxide scales (common in hot-rolled products).​

Rolling Mill Gearboxes: Angular contact ball bearings (7000 series)​

Role: Transmit high torque with low noise; maintain precision under variable loads to avoid gear meshing errors.​

3. Application in Forging & Extrusion Equipment​

Forging presses and extruders require bearings to withstand extreme impact loads (up to 10,000 kN for large forging presses) and short-term overloads, while ensuring precise movement of sliding blocks or rams.​

Forging Press Sliding Block Guide: Needle roller bearings (NA series)​

Advantage: Compact radial structure saves installation space; high load density handles heavy impact without deformation.​

Aluminum Extruder Screw Drive: Cylindrical roller bearings (NJ series) with modified heat treatment​

Technical Upgrade: Surface carburizing (hardness ≥60 HRC) enhances wear resistance; optimized internal clearance adapts to thermal expansion of the screw during extrusion.​

4. Application in Auxiliary Metallurgical Equipment​

Auxiliary equipment (conveyor belts, dust removal systems, cooling rolls) supports the continuity of metallurgical processes, and bearings here focus on long service life and low maintenance.​

Conveyor Belts for Ore/Scrap Steel: Spherical roller bearings (24100 series) with waterproof seals​

Feature: Double-lip seals (contact type) prevent mud and water intrusion; corrosion-resistant outer rings (galvanized treatment) adapt to outdoor or damp workshops.​

Continuous Casting Cooling Rolls: Deep groove ball bearings (6300 series) with stainless steel rings​

Reason: Stainless steel (304 material) resists corrosion from cooling water; high-speed stability (up to 3000 rpm) ensures uniform cooling of cast slabs.​

5. Core Technical Solutions for Metallurgical Bearings​

To meet the harsh conditions of metallurgical equipment, bearings adopt targeted design and material upgrades:​

Material Optimization: High-purity bearing steel (SUJ2 modified) with reduced oxygen content (≤15 ppm) to improve fatigue life by 30% compared to standard steel.​

Heat Treatment: Nitriding or carbonitriding processes enhance surface hardness (up to 1000 HV) and high-temperature resistance, suitable for smelting and rolling mill applications.​

Sealing & Lubrication: High-temperature resistant seals (PTFE material) paired with lithium complex grease (operating temperature -20°C to 250°C) reduce maintenance frequency by 50%.​

Structural Innovation: Split spherical roller bearings (for large rolling mills) enable on-site replacement without disassembling heavy equipment, cutting downtime from 8 hours to 2 hours.​

6. Typical Application Case​

A leading steel mill in Europe upgraded the bearings of its 2050 mm hot rolling mill work rolls from standard spherical roller bearings to customized high-temperature resistant models (23280 CA/W33):​

Before Upgrade: Bearings required replacement every 3 months due to heat-induced wear; unplanned downtime caused 5% production loss.​

After Upgrade: Service life extended to 9 months; maintenance cost reduced by 40%; rolling mill efficiency increased by 8% due to stable operation.