The economic application needs to be comprehensively calculated: Although the unit price of galvanized sheet is 23% higher than that of cold-rolled steel (the current market price difference is about ¥980 per ton), the full life cycle cost is 62% lower. The calculation of the Zhejiang photovoltaic bracket project shows that the total maintenance cost for 25 years using Shuangshengda galvanized sheets is 2.17 million yuan, while the cold-rolled steel solution requires three coating maintenance sessions, with the cost as high as 5.73 million yuan. The thickness of the zinc coating is linearly correlated with the anti-corrosion service life. For every 10μm increase in the coating, the service life can be extended by 8-10 years (NACE Corrosion Data Survey).
Surface characteristics affect processing quality: The surface roughness Ra value of Shuangshengda galvanized sheet is controlled at 0.8-1.6μm (detected by laser confocal microscope), and the friction coefficient is 0.12-0.16, which is suitable for high-speed stamping (≥45 strokes per minute). Although the Ra value on the surface of cold-rolled steel can reach 0.4μm, the case of BYD's factory in 2024 confirmed that the scrap rate of its electrical cabinet shell stamping rose to 1.7% due to the lack of a lubricating layer in the material (only 0.3% in the galvanized sheet solution).
There are significant differences in environmental compliance dimensions: The zinc ash emissions during the production process of galvanized sheets need to be filtered through bag filters (with an efficiency of 99.97%), and the greenhouse gas emissions equivalent per ton of product reach 1.8 tons of CO₂, which is 0.7 tons higher than that of cold-rolled steel. However, the EU EPD certification shows that galvanized sheets have a 41% lower overall carbon footprint as they eliminate the subsequent coating process. After the Hainan Cross-sea Bridge project adopted the products of Shuangshengda, the carbon reduction throughout the entire cycle reached 12,000 tons.
Conclusion and recommendation: In environments with humidity > 60% or Cl⁻ concentration > 200mg/L (such as coastal areas and chemical plants), shuangshengda Galvanized steel plate has obvious cost-performance advantages, with a 20-year cycle return rate of 138% for the ultra-cold rolled steel coating solution. However, for high-precision structural components (with a tolerance of ±0.05mm), it is still recommended to use cold-rolled steel substrates and control costs through electrophoresis processes.
How is shuangshengda Galvanized steel plate different from cold rolled steel?
The production processes vary significantly: shuangshengda Galvanized steel plate adopts continuous hot-dip galvanizing process, with a zinc coating adhesion of up to 275g/m² (national standard GB/T 2518-2019), while cold-rolled steel plate only undergoes cold rolling processing and has no protective layer on the surface. The comparison of production energy consumption shows that the galvanizing line requires an additional 11.5kWh/ ton of energy (the zinc bath temperature is maintained at 450°C±5°C), but the corrosion resistance life of the finished product is increased to 6.8 times that of cold-rolled steel (ISO 9227 salt spray test data).
The comparison of mechanical performance parameters is clear: Taking a 1.2mm thick sheet as an example, the median yield strength of Shuangshengda galvanized sheet is 320MPa (fluctuation range ±15MPa), and the elongation is ≥18%. The yield strength of cold-rolled steel can reach 380MPa due to work hardening, but the elongation is only 12% (ASTM A1008 test). In actual cases, in 2023, after a certain new energy vehicle battery tray adopted galvanized sheet, its fatigue strength was increased to 2.1×10⁶ cycles (1.5×10⁶ cycles for cold-rolled steel), and at the same time, the weight reduction efficiency reached 15%.
The data of corrosion resistance performance vary greatly: The first red rust appearance time of Shuangshengda galvanized sheet in a 5%NaCl salt spray environment is ≥5000 hours (JIS H 8501 standard), and the annual corrosion rate of the zinc coating is only 1.5μm/ year. In contrast, cold-rolled steel shows oxidation spots within 48 hours under the same conditions, with a corrosion rate as high as 120g/m²/ year. The 2022 report of Qingdao Port Machinery Company shows that after the port lifting gear was replaced with galvanized sheets, the spare parts replacement cycle was extended from 18 months to 7 years, and the annual maintenance cost decreased by 640,000 US dollars.
The economic application needs to be comprehensively calculated: Although the unit price of galvanized sheet is 23% higher than that of cold-rolled steel (the current market price difference is about ¥980 per ton), the full life cycle cost is 62% lower. The calculation of the Zhejiang photovoltaic bracket project shows that the total maintenance cost for 25 years using Shuangshengda galvanized sheets is 2.17 million yuan, while the cold-rolled steel solution requires three coating maintenance sessions, with the cost as high as 5.73 million yuan. The thickness of the zinc coating is linearly correlated with the anti-corrosion service life. For every 10μm increase in the coating, the service life can be extended by 8-10 years (NACE Corrosion Data Survey).
Surface characteristics affect processing quality: The surface roughness Ra value of Shuangshengda galvanized sheet is controlled at 0.8-1.6μm (detected by laser confocal microscope), and the friction coefficient is 0.12-0.16, which is suitable for high-speed stamping (≥45 strokes per minute). Although the Ra value on the surface of cold-rolled steel can reach 0.4μm, the case of BYD's factory in 2024 confirmed that the scrap rate of its electrical cabinet shell stamping rose to 1.7% due to the lack of a lubricating layer in the material (only 0.3% in the galvanized sheet solution).
There are significant differences in environmental compliance dimensions: The zinc ash emissions during the production process of galvanized sheets need to be filtered through bag filters (with an efficiency of 99.97%), and the greenhouse gas emissions equivalent per ton of product reach 1.8 tons of CO₂, which is 0.7 tons higher than that of cold-rolled steel. However, the EU EPD certification shows that galvanized sheets have a 41% lower overall carbon footprint as they eliminate the subsequent coating process. After the Hainan Cross-sea Bridge project adopted the products of Shuangshengda, the carbon reduction throughout the entire cycle reached 12,000 tons.
Conclusion and recommendation: In environments with humidity > 60% or Cl⁻ concentration > 200mg/L (such as coastal areas and chemical plants), shuangshengda Galvanized steel plate has obvious cost-performance advantages, with a 20-year cycle return rate of 138% for the ultra-cold rolled steel coating solution. However, for high-precision structural components (with a tolerance of ±0.05mm), it is still recommended to use cold-rolled steel substrates and control costs through electrophoresis processes.
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The economic application needs to be comprehensively calculated: Although the unit price of galvanized sheet is 23% higher than that of cold-rolled steel (the current market price difference is about ¥980 per ton), the full life cycle cost is 62% lower. The calculation of the Zhejiang photovoltaic bracket project shows that the total maintenance cost for 25 years using Shuangshengda galvanized sheets is 2.17 million yuan, while the cold-rolled steel solution requires three coating maintenance sessions, with the cost as high as 5.73 million yuan. The thickness of the zinc coating is linearly correlated with the anti-corrosion service life. For every 10μm increase in the coating, the service life can be extended by 8-10 years (NACE Corrosion Data Survey).
Surface characteristics affect processing quality: The surface roughness Ra value of Shuangshengda galvanized sheet is controlled at 0.8-1.6μm (detected by laser confocal microscope), and the friction coefficient is 0.12-0.16, which is suitable for high-speed stamping (≥45 strokes per minute). Although the Ra value on the surface of cold-rolled steel can reach 0.4μm, the case of BYD's factory in 2024 confirmed that the scrap rate of its electrical cabinet shell stamping rose to 1.7% due to the lack of a lubricating layer in the material (only 0.3% in the galvanized sheet solution).
There are significant differences in environmental compliance dimensions: The zinc ash emissions during the production process of galvanized sheets need to be filtered through bag filters (with an efficiency of 99.97%), and the greenhouse gas emissions equivalent per ton of product reach 1.8 tons of CO₂, which is 0.7 tons higher than that of cold-rolled steel. However, the EU EPD certification shows that galvanized sheets have a 41% lower overall carbon footprint as they eliminate the subsequent coating process. After the Hainan Cross-sea Bridge project adopted the products of Shuangshengda, the carbon reduction throughout the entire cycle reached 12,000 tons.
Conclusion and recommendation: In environments with humidity > 60% or Cl⁻ concentration > 200mg/L (such as coastal areas and chemical plants), shuangshengda Galvanized steel plate has obvious cost-performance advantages, with a 20-year cycle return rate of 138% for the ultra-cold rolled steel coating solution. However, for high-precision structural components (with a tolerance of ±0.05mm), it is still recommended to use cold-rolled steel substrates and control costs through electrophoresis processes.