Complete Rolling Mill Bearing Solution for a Major Steel Enterprise

Project Background

The customer is a major domestic steel group whose hot-rolling production line has an annual capacity of over 5 million tons. The rolling mill bearings on the line had long suffered from short service life and high maintenance frequency, seriously affecting line efficiency and production costs.

Operating-Condition Analysis

• Operating temperature: 80-120℃
• Radial load: Extremely high (over 500kN)
• Speed range: 200-800rpm
• Environmental characteristics: High temperature, heavy load, water vapor, and mill scale contamination

Solution

Bearing Selection: Based on the operating conditions, four-row tapered roller bearings were recommended for the work rolls, and spherical roller bearings for the backup rolls.

Material Upgrade: High-purity vacuum-degassed steel (GCr15SiMn) was adopted to improve fatigue life.

Sealing Optimization: A dedicated labyrinth seal structure was designed to effectively prevent the ingress of water vapor and mill scale.

Lubrication Solution: High-temperature lithium-based grease was supplied, with optimized lubrication intervals and grease quantity.

Results

• Bearing service life extended by more than 40%
• Unplanned downtime reduced by 60%
• Annual maintenance costs reduced by approximately RMB 1.2 million
• Overall line efficiency improved by 5%