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• Release time：2025-09-04 08:00
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【概要描述】The Impact of Descaling Systems on Product Quality in Second-Hand Hot Rolling Mills​ Descaling systems are essential pre-processing components in second-hand hot rolling mills, responsible for removing oxide scale (scale) from the surface of steel slabs or billets before rolling. Their effectiveness directly influences the surface quality of hot-rolled products and the service life of rolling equipment.​ Surface Quality Improvement​ Oxide scale formed on the surface of steel during heating (at 1100-1250°C in the reheating furnace) is brittle and porous. If not removed by the descaling system, it will be pressed into the steel surface during rolling, forming scale pits, scratches, or uneven surfaces. In well-designed second-hand hot rolling mills, high-pressure water descaling systems (operating pressure 15-30 MPa, water flow rate 800-1500 L/min) can remove over 95% of the scale. This results in hot-rolled coils with surface roughness Ra ≤5μm, meeting the requirements of automotive exterior panels or structural steel for construction. For second-hand hot rolling mills processing high-grade steel (e.g., API X70 for pipelines), effective descaling can reduce surface defect rates by 50-60%.​ Roll Protection and Longevity Extension​ Pressed-in scale acts as an abrasive between the rolling rolls and the steel, accelerating roll wear. In second-hand hot rolling mills with outdated descaling systems, roll replacement frequency can increase by 30-40%, leading to higher maintenance costs and more unplanned downtime. A high-efficiency descaling system in second-hand hot rolling mills prevents scale from entering the roll gap, reducing roll wear by 20-25% and extending roll life from 1500 to 1800 tons per roll. This is particularly important for second-hand mills with aging roll change mechanisms, as fewer roll changes minimize the risk of mechanical failures during maintenance.​ Energy Consumption Optimization​ While descaling systems consume water and electricity, their proper operation can indirectly reduce the energy consumption of second-hand hot rolling mills. Scale on the steel surface increases friction between the rolls and the material, requiring higher rolling force (by 10-15%) to achieve the desired thickness reduction. By removing scale, the descaling system reduces rolling force, lowering the power consumption of the main drive motor (typically 5000-15000 kW) by 5-8%. Additionally, modern descaling systems in refurbished second-hand hot rolling mills use water recycling units, reducing fresh water consumption by 60-70% (from 1.5 to 0.6 m³ per ton of steel).​ Maintenance and Optimization Strategies​ To ensure the effectiveness of descaling systems in second-hand hot rolling mills:​ Inspect the descaling nozzles daily for clogging or wear; replace nozzles with flow rate deviations exceeding 10%.​ Check the high-pressure pump pressure and flow rate weekly; adjust the pump speed to maintain the recommended operating parameters.​ Clean the water filtration system monthly to remove scale particles and prevent nozzle clogging.​ Descale the reheating furnace walls quarterly to prevent scale from falling onto the steel surface during slab discharge.​ For second-hand hot rolling mills processing thick slabs (thickness ≥200mm), upgrading the descaling system to include a secondary descaling unit after the first rolling stand can further improve scale removal efficiency, especially for scale formed during the initial rolling pass.​ For more information, please pay attention to the website of Jinyujie Mechanical and Electrical Used Pipe Mill Supplier：www.usedpipemill.com