As the core component of rolling operations, roll condition directly impacts product precision and equipment stability. Neglecting maintenance frequently results in premature wear or cracks, driving up operational costs. Below is a streamlined breakdown of critical roll maintenance practices across two key scenarios:

I. During Operation: Real-Time Monitoring & Process Control

Rolls endure complex stresses during use—prompt intervention prevents minor flaws from escalating into major failures.

1. Condition Monitoring

- Visual Checks: Conduct hourly inspections to spot issues like metal sticking (clean with resin scrapers, never steel spatulas), microcracks (replace rolls immediately if cracks exceed 10mm), and surface spalling.

- Sensory & Instrument Aids: Listen for abnormal noises (indicative of bearing wear) and check bearing housing temperature (keep below 70°C). Use infrared thermometers to maintain surface temperatures (200–350°C for hot-rolling rolls; 30–60°C for cold-rolling rolls) and vibration sensors to ensure amplitude stays under 0.05mm.

2. Process Optimization

- Adhere to design limits for rolling force (e.g., ≤2000kN for φ500mm forged steel rolls) to avoid permanent deformation.

- Stabilize rolling temperatures (keep fluctuations within ±50°C for hot rolling) and ensure consistent cooling—use at least 50L/(min·m) of water for hot-rolling rolls, and never resume cooling abruptly if water flow is interrupted.

II. Post-Operation: Cleaning, Repair & Protection

Proper handling after rolls are taken offline is critical to extending their next service cycle.

1. Thorough Cleaning: Rinse rolls with high-pressure water (0.3–0.5MPa) to remove oxide scale and oil, then dry with lint-free cloths or compressed air (0.2MPa) to eliminate residue.

2. Inspection & Repair

- Perform ultrasonic testing (scrap rolls if internal cracks exceed 5mm) and magnetic particle testing for surface flaws. Check roundness (tolerance ≤0.01mm) and surface roughness (Ra ≤0.4μm for cold-rolling rolls).

- Grind minor wear (e.g., ≤0.2mm for cold-rolling rolls) and use laser cladding to repair spalled areas—restore surface hardness to HRC 55–60.

3. Rust Prevention: Apply anti-rust oil in a 0.1–0.2mm thick film. For rolls idle over 1 month, wrap them in plastic film for extra protection.

III. Common Maintenance Mistakes to Avoid

Misconception	Correct Practice
Using steel spatulas to remove stuck metal	Clean with resin scrapers or soft wire brushes
Refilling cooling water immediately after interruption	Let rolls cool to below 100°C first
Storing rolls without cleaning	Rinse with high-pressure water and dry thoroughly
Over-grinding during repairs	Limit single grinding passes to ≤0.5mm