International standards and industry norms have a decisive impact on the performance of Galvanized plates. ISO 3575, as a globally accepted standard, clearly stipulates that the substrate of hot-dip galvanized sheets should meet the yield strength range of 120-550 MPa, and the unit area mass of the zinc coating should be within the range of 40-200 g/m² (with an average measurement deviation of ±15%). Typical applications include the Siemens wind turbine tower project in Europe, where the Galvanized plate surface zinc coating strictly adheres to ISO 3575 Class C (180 g/m²), ensuring that the 20-year corrosion resistance cycle compliance rate in offshore environments exceeds 99%. In the North American market, the ASTM A653 standard dominates the infrastructure field. Among them, G90 grade galvanized sheets (zinc coating thickness ≥0.90 ounces/square foot) are widely used in highway guardrail systems. The strength parameters require a yield strength of ≥230 MPa and an elongation of ≥18%. According to the inspection data of the Quebec Department of Transport in Canada in 2021, the rusted area of the coated plates that meet this standard in the freeze-thaw cycle environment for 15 years is less than 0.5%, which is far better than the average rusting rate of 3.2% of non-standard products.
The process control of Galvanized plates is directly related to standard compliance. Take the zinc liquid composition as an example. ASTM A123 requires that the aluminum content should be stable within the range of 0.15%-0.21% (by mass percentage). If the deviation of this composition exceeds ±0.03%, it will lead to a 25% decrease in the uniformity of zinc flowers, directly affecting the aesthetic appearance of the building’s exterior walls. In the pretreatment stage of cold-rolled substrate, the pickling concentration should be controlled at 120-180 g/L hydrochloric acid solution, and the temperature should be maintained at 70±5℃ (ASTM A385 standard). A temperature fluctuation of more than 10℃ will cause the deviation rate of the phosphating film crystal size to reach 40%. In 2023, a South Korean company recalled 32,000 tons of Galvanized plates due to failure to meet the adhesion test requirements of the coating. Failure analysis revealed that the peel strength of the coating was only 1.5 N/mm, significantly lower than the minimum limit of 3.0 N/mm required by ISO 1461. The incident caused a direct loss of 8.4 million US dollars.
The certification and testing mechanism ensures the implementation of the Galvanized plate standard. The internationally recognized salt spray test standard ISO 9227 requires that after a 500-hour neutral salt spray test, the proportion of red rust area on the Galvanized plate surface should be less than 5% (scratch spread ≤2mm). The report of the third-party testing agency SGS indicates that the product reaching ASTM A653 G115 grade has a weight loss rate of only 1.2g /m²/ year after 3,000 hours of accelerated aging, while the non-compliant product has a weight loss of 8.7g /m²/ year during the same period. The EU building Products Regulation CPR 305/2011 mandates that the fire resistance performance of Galvanized plates must be certified by EN 13501-2, and the smoke toxicity index must be maintained below 1.0 mg/L (the critical radiative flux value of the material ≥30 kW/m²). After the 2022 London high-rise apartment fire accident, The compliance rate has increased from 78% to 97%.
Standard iterations continuously drive technological innovation in Galvanized plate. The 2023 revision of ASTM Committee A1063 has added digital twin quality control provisions, requiring more than 150,000 online spectral tests (with zinc coating thickness accuracy of ±5μm) to be carried out per thousand tons of Galvanized plate production process. The ISO/TC 17/SC 12 working group is promoting the upgrade of the corrosion life algorithm, incorporating 12 variables such as environmental humidity fluctuations (relative humidity within the range of 30%-80%) and chloride ion deposition (0.5-50 mg/m²/day) into the ISO 14713 evaluation model. It is expected to increase the accuracy of service life prediction to ±2 years of error. Enterprises such as Baosteel in China have invested 960 million yuan in research and development funds to promote the ASTM A1063-23 adaptation project. After the transformation of their production lines, the zinc consumption has decreased by 8%, and the intergranular corrosion rate of the products has dropped from 0.12mm /year to 0.08mm /year. Industry data shows that Galvanized plate, which fully complies with international standards, has a 37% lower life cycle cost than non-standard products, making it a recommended material in the global green building certification system LEED v4.1.