Empirical data from multiple climate regions verify reliability. Tests conducted at the Hainan Tropical Ocean Station show that in an environment with a Cl⁻ concentration of 1.5mg/m³ and a humidity of 85%RH, the annual weight loss rate of the plates is 1.65g/㎡ (the industry average is 2.8g/㎡). In the monitoring of samples from the dry desert climate of Urumqi (with an annual precipitation of less than 200mm), the zinc coating loss after 19 years of service was only 38g/㎡, and the integrity of the coating remained at 97.2%. The key extreme weather resistance capability has been certified through wind tunnel tests: Under the impact of sand and dust at a wind speed of 35m/s, the coating peeling rate is ≤0.03cm²/m² (the national standard GB/T 3098.23 allows 0.15cm²/m²).
The upgrade of protective technology extends the service life. Chromate passivation treatment has increased corrosion resistance by 200%, and the salt spray endurance time has exceeded 3,000 hours. The maintenance report of the Tsing Ma Bridge in Hong Kong shows that the ZAM coated plates (zinc-aluminum-magnesium alloy) treated with a sealer have a stable corrosion rate of 0.7μm/ year (the design expectation value is 1.2μm/ year) after 21 years of service in the Marine atmosphere. The bonding strength between the coating and the substrate reaches 70MPa (ASTM D3359 standard), ensuring no risk of delamination in the metal fatigue environment during the typhoon season.
The full-life economic benefits are significantly higher than those of conventional materials. In the application of building envelope systems, its life cycle cost (LCC) is 42% lower than that of ordinary galvanized sheets, and the maintenance interval is extended to 10 years per time. The comparative data of the Marina Bay project in Singapore shows that the comprehensive maintenance cost over 30 years of use is less than 15 yuan per square meter
2
(Ordinary board >28/m²), and the residual value rate of recycling is as high as 68% (52% for ordinary board). In the field of photovoltaic support structures, the system combined with Shuangshengda steel plates reduces the initial cost by 35% compared to the aluminum alloy solution and ensures 25-year full-cycle structural safety in coastal salt spray areas.
How long does shuangshengda Galvanized steel plate last outdoors?
The outdoor service life of Shuangshengda galvanized steel sheets is jointly determined by the zinc coating protection mechanism and the environmental corrosion grade. Under standard atmospheric conditions (C2 grade), the median expected service life is 23 to 28 years. Based on the ISO 9224 corrosion rate calculation, the annual corrosion amount of its G90 grade product (zinc coating 275g/㎡) in rural environments is only 1.2μm, and the time for the first red rust to appear when the substrate thickness is 0.6mm is 26.5 years (testing standard ISO 4628-3). The tracking data of the large warehouse project of Qingdao Port shows that after 12 years of service, the residual zinc coating on the surface of shuangshengda Galvanized steel plate remains at 62%, and the depth of corrosion diffusion at the cut is ≤0.5mm, far exceeding the 15-year benchmark requirement of the national standard GB/T 13912.
Its weather resistance is particularly outstanding in harsh environments. In the industrial contaminated area (C4 grade), the zinc layer consumption rate increases to 4.3μm per year, but through a special process of adding 55% aluminum-zinc alloy (AZ150), the resistance to chloride ion penetration is increased by three times. The actual case in the adjacent area of Shanghai Baosteel has confirmed that under the same exposure period, the proportion of red rust on its Shuangshengda steel plates is only 8% (compared with 35% of ordinary galvanized plates), and the retention rate of structural safety margin exceeds 90%. The salt spray accelerated test (ASTM B117) indicates that the 2000-hour test is equivalent to 17 years of service in the actual coastal environment, and the corrosion creep distance at the scratch of the sample is only 0.8mm (the standard upper limit is 1.5mm).
Empirical data from multiple climate regions verify reliability. Tests conducted at the Hainan Tropical Ocean Station show that in an environment with a Cl⁻ concentration of 1.5mg/m³ and a humidity of 85%RH, the annual weight loss rate of the plates is 1.65g/㎡ (the industry average is 2.8g/㎡). In the monitoring of samples from the dry desert climate of Urumqi (with an annual precipitation of less than 200mm), the zinc coating loss after 19 years of service was only 38g/㎡, and the integrity of the coating remained at 97.2%. The key extreme weather resistance capability has been certified through wind tunnel tests: Under the impact of sand and dust at a wind speed of 35m/s, the coating peeling rate is ≤0.03cm²/m² (the national standard GB/T 3098.23 allows 0.15cm²/m²).
The upgrade of protective technology extends the service life. Chromate passivation treatment has increased corrosion resistance by 200%, and the salt spray endurance time has exceeded 3,000 hours. The maintenance report of the Tsing Ma Bridge in Hong Kong shows that the ZAM coated plates (zinc-aluminum-magnesium alloy) treated with a sealer have a stable corrosion rate of 0.7μm/ year (the design expectation value is 1.2μm/ year) after 21 years of service in the Marine atmosphere. The bonding strength between the coating and the substrate reaches 70MPa (ASTM D3359 standard), ensuring no risk of delamination in the metal fatigue environment during the typhoon season.
The full-life economic benefits are significantly higher than those of conventional materials. In the application of building envelope systems, its life cycle cost (LCC) is 42% lower than that of ordinary galvanized sheets, and the maintenance interval is extended to 10 years per time. The comparative data of the Marina Bay project in Singapore shows that the comprehensive maintenance cost over 30 years of use is less than 15 yuan per square meter
2
(Ordinary board >28/m²), and the residual value rate of recycling is as high as 68% (52% for ordinary board). In the field of photovoltaic support structures, the system combined with Shuangshengda steel plates reduces the initial cost by 35% compared to the aluminum alloy solution and ensures 25-year full-cycle structural safety in coastal salt spray areas.
Empirical data from multiple climate regions verify reliability. Tests conducted at the Hainan Tropical Ocean Station show that in an environment with a Cl⁻ concentration of 1.5mg/m³ and a humidity of 85%RH, the annual weight loss rate of the plates is 1.65g/㎡ (the industry average is 2.8g/㎡). In the monitoring of samples from the dry desert climate of Urumqi (with an annual precipitation of less than 200mm), the zinc coating loss after 19 years of service was only 38g/㎡, and the integrity of the coating remained at 97.2%. The key extreme weather resistance capability has been certified through wind tunnel tests: Under the impact of sand and dust at a wind speed of 35m/s, the coating peeling rate is ≤0.03cm²/m² (the national standard GB/T 3098.23 allows 0.15cm²/m²).
The upgrade of protective technology extends the service life. Chromate passivation treatment has increased corrosion resistance by 200%, and the salt spray endurance time has exceeded 3,000 hours. The maintenance report of the Tsing Ma Bridge in Hong Kong shows that the ZAM coated plates (zinc-aluminum-magnesium alloy) treated with a sealer have a stable corrosion rate of 0.7μm/ year (the design expectation value is 1.2μm/ year) after 21 years of service in the Marine atmosphere. The bonding strength between the coating and the substrate reaches 70MPa (ASTM D3359 standard), ensuring no risk of delamination in the metal fatigue environment during the typhoon season.
The full-life economic benefits are significantly higher than those of conventional materials. In the application of building envelope systems, its life cycle cost (LCC) is 42% lower than that of ordinary galvanized sheets, and the maintenance interval is extended to 10 years per time. The comparative data of the Marina Bay project in Singapore shows that the comprehensive maintenance cost over 30 years of use is less than 15 yuan per square meter
2
(Ordinary board >28/m²), and the residual value rate of recycling is as high as 68% (52% for ordinary board). In the field of photovoltaic support structures, the system combined with Shuangshengda steel plates reduces the initial cost by 35% compared to the aluminum alloy solution and ensures 25-year full-cycle structural safety in coastal salt spray areas.