1.Why must leveling equipment be protected from scratches?
Core Value Protection: The surface quality of cold-rolled coils (especially high-grade automotive steel, appliance steel, tin-plated substrate, etc.) is their core value. A single scratch can reduce them from a high-grade product to scrap.
Process Source: Leveling is the starting point for all subsequent processing. Pollution at the source has endless consequences.
Equipment Characteristics: Leveling lines have many pieces of equipment, complex roller systems, and numerous contact points between the steel sheet and the equipment, resulting in a high concentration of scratch risk points.
2.What are the risk points and common causes of open-book exams?
Uncoiling machine drum: The surface of the drum's fan-shaped plate has dents, rust, or hard particles adhering to it; excessive tension has caused damage to the inner coil.
Repair the drum surface with chrome plating or a polymer protective sleeve; perform regular cleaning and inspection; optimize uncoiling tension.
3.What are the risk points in the leveling/straightening section?
Straightening/Leveling Rolls
This is the most common area of occurrence. Rollers with worn surfaces, pits, or hard objects adhering to them are directly rolled over the steel plate surface under high pressure.
The roller material and precision requirements are the highest; a continuously operating roller cleaning device must be installed; and a strict roller system inspection system must be established.
4.What are the risk points in the shearing and stacking sections?
Tabletop and Dragging
After shearing, the steel plate is dragged across the tabletop, generating friction.
To prevent contact friction, install an air cushion device on the tabletop or use a swivel ball bearing table, allowing the steel plate to "float" on the air film.
5.What are the key design and management principles for scratch prevention?
Minimize and soften contact points: All points of contact with the steel plate surface should either be made flexible (e.g., polyurethane-coated rollers, nylon guides) or ensured to be rigid contacts with extremely high hardness and high surface finish (e.g., hardened steel mirror-finish rollers).
Cleanliness is the lifeline: Establish a strict equipment cleaning system to ensure that all roller surfaces and channels are free of any hard particles.
Systematized equipment maintenance: Regularly perform eddy current testing or manual microscopic inspection on the entire roller system to promptly identify and replace rollers with minor defects. Roll cleaners, scrapers, and other devices must be kept in effective working condition.
Standardized operation: Train operators to fully understand the impact of parameters such as tension, speed, and guide clearance on surface quality, and ensure strict adherence to operating procedures.