Both coil and flat forms of Galvanized steel plate have achieved industrial-scale production. Coils (with widths ranging from 600 to 2000mm) account for approximately 75% of the global market share, while flat plates (standard sizes ranging from 1200x2400mm to 1500x6000mm) make up 25%. According to the 2023 report of the World Steel Association, the maximum line speed of the coil production line can reach 180m/min, the unit production cost is 8 to 12 US dollars per ton lower than that of flat plates, and the logistics efficiency is improved by 30% (a single coil weighing 25 tons can reduce the frequency of loading and unloading by 50%). The automotive manufacturing industry uses continuous coil stamping to reduce the scrap rate to 4%, while the aircraft manufacturing industry prefers flat plates (with a thickness of 0.5-3mm and a tolerance of ±0.15mm) to meet the precision requirements of 5-axis cutting.
The advantage of coil materials lies in the benefits of deep processing. Cases in the home appliance industry show that after Haier introduced the fully automatic coil uncoiling line (with a speed of 120m/min) in 2022, the production cycle of the shell was compressed from 7 days to 48 hours, the material utilization rate increased by 18%, and the annual cost savings exceeded 20 million yuan. In terms of electromagnetic characteristics, when the curvature radius of the coil material is ≥300mm, the magnetic permeability fluctuation is ≤0.5%, ensuring the consistency of the performance of the motor silicon steel sheet. However, the transportation of coil materials requires special equipment (such as a 610mm diameter steel coil saddle), and the logistics cost accounts for 15% of the selling price, which is 5 percentage points higher than that of flat plates.
The tablet form meets customized scenarios. The building curtain wall project requires a single board size tolerance of ±1mm (for example, the Shanghai Tower uses 1600x12000mm super-long boards), and reduces on-site welding points by 70% through fixed-length shearing. Data from the environmental protection field shows that the waste chip rate of flat plate reprocessing is only 2%, significantly lower than the 12% edge material loss during the opening of coil materials. For the 2024 Longyan Energy photovoltaic bracket order verification, the anti-corrosion life of the flat galvanized sheet (zinc coating 180g/m²) after laser cutting is maintained for 25 years, which is 5 years longer than that of the traditional cutting process.
The supply chain requires a differentiated strategy. The inventory turnover of coil materials needs to be efficient (with an average turnover period of 15 days). Referring to the intelligent warehouse system of POSCO, the detection accuracy of coil diameter is ±0.2mm, and the storage density is optimized by 35%. For tablets, the JIT mode (such as the cooperation project between Toyota and Baosteel) is adopted, and production based on orders reduces inventory costs by 40%. In international transportation, the sea loading capacity of coil materials reaches 200 tons per 40-foot container, while that of flat plates is only 120 tons due to stacking restrictions, resulting in a freight rate difference of up to 30%.
Technological innovation promotes the integration of forms. Laser spot welding technology (such as ThyssenKrupp ‘s Tailored Blanks production line) enables direct conversion from coil to flat plate, reducing slitting energy consumption by 0.8kWh per ton and achieving weld strength of 95% of the base material. By 2025, the EU’s green steel policy requires that the proportion of recycled materials exceed 30%, and that the continuous galvanizing line for coil materials be 50% more compatible with scrap steel than the flat plate production line, with the carbon emission intensity reduced to 0.8tCO₂ per ton. The digital twin system (Siemens platform) can predict the optimal form selection, saving customers’ procurement costs by up to 12%.
Sustainable development drives morphological evolution. In the wind power industry, coil materials (plate thickness 4mm) are used to manufacture the conical sections of tower cylinders, reducing flange interfaces by 60% and extending the structural lifespan by 20 years. The solar bracket market prefers flat plates (with a 500-hour salt spray test for anti-corrosion coating), which are convenient for on-site cutting to adapt to complex terrains. Global trends show that by 2030, the proportion of automated coil production lines will rise to 80%, while custom flat plates will maintain an annual growth rate of 15% in the small-batch sector.