1.How to choose zinc layer for different usage environments?
Mildly corrosive environments: Choose 80-120g/m² (single-sided zinc coating thickness of approximately 5.6-8.4μm).
Applicable scenarios: Dry indoor environments (such as appliance interiors, furniture panels, warehouse shelves), and indoor buildings in low-humidity areas (such as office partitions and ceilings).
Reason: These environments have low moisture and dust levels and are virtually free of corrosive media. A zinc coating only requires basic protection; a thicker coating may increase costs.
Moderately corrosive environments: Choose 120-180g/m² (single-sided zinc coating thickness of approximately 8.4-12.6μm).
Applicable scenarios: Ordinary outdoor environments (such as building walls and roofs in non-industrial areas), humid indoor environments (such as kitchen appliance housings and bathroom fixtures), and lightly polluted areas (such as suburban areas).
Reason: These environments may experience a small amount of rain and humidity, as well as occasional dust accumulation. A medium zinc coating balances protection and cost, preventing the zinc coating from being completely depleted in a short period of time. For severely corrosive environments: Choose 180-275g/m² (approximately 12.6-19.2μm zinc coating on one side), or even higher.
Applicable Applications: Highly humid and salty environments (such as building exteriors/roofs near the seaside and coastal cities, and dock facilities), industrial areas (such as those around chemical plants and power plants, exposed to acid rain and industrial exhaust), and locations exposed to long-term outdoor conditions (such as outdoor billboards and shipping containers).
Reason: In these environments, salt spray and acidic media can rapidly erode the zinc coating. A thicker zinc coating can extend the "sacrificial protection" period. For example, in coastal environments, a 180g/m² zinc coating can extend its lifespan by over 30% compared to a 120g/m² coating.
2.Why should we avoid excessive zinc layer thickness during complex processing?
For complex processing (e.g., deep drawing, multiple bending, or special-shaped parts like appliance panels or automotive parts), we recommend selecting a zinc coating thickness of 120-180g/m² and avoiding 200g/m². Excessively thick zinc coatings can cause brittle fracture during processing, negatively impacting product quality.
For simple processing (e.g., shearing and rolling, such as corrugated sheet and C-shaped steel for construction), you can select a thickness tailored to the specific application (even 275g/m² is acceptable, as processing has minimal impact on the zinc coating).
3.Balancing "cost and lifespan", how to choose the right zinc coating?
If the product is intended for long-term use (e.g., pre-coated building panels with an expected lifespan of 20 years or more): Even in highly corrosive environments, a thicker zinc coating (e.g., 200-275g/m²) is recommended, despite the higher cost. This avoids premature replacement due to rust and is more cost-effective.
If the product is intended for short-term use (e.g., a temporary outdoor shed with an expected lifespan of less than 5 years): Even for outdoor use, a 120-150g/m² coating is acceptable. There's no need to pursue an excessively thick zinc coating; cost control is more critical.
4.How to quickly determine the thickness of the zinc layer?
First, determine the environment: Is it a dry indoor environment (light corrosion), an outdoor environment (medium corrosion), or a coastal/industrial environment (heavy corrosion)?
Next, consider the processing requirements: simple shearing or complex stamping?
Finally, consider the expected lifespan: balancing "zinc layer thickness - protection period - cost," and select the appropriate range (80-120g/m², 120-180g/m², 180-275g/m²).
5.Does the thickness of the zinc layer of the color-coated galvanized coil affect its service life?
The thickness of the zinc layer of the color-coated galvanized coil directly affects its service life. The two are usually "positively correlated" - under the same use environment and coating quality, the thicker the zinc layer, the longer the protection period of the steel plate substrate and the longer the overall service life of the product.