1.What is the difference in zinc layer thickness?
Assuming a 1g/m² coating is approximately equal to 0.0071μm thickness, the zinc layer thickness of DX51D 80G is approximately 11μm, and the zinc layer thickness of DX51D 100G is approximately 14μm.
2.What is the difference between zinc layer weight and corrosion resistance?
DX51D 80G:
Total zinc coating weight on both sides = 80 g/m² (denoted as Z80 or 80G).
Weak corrosion resistance: Suitable for dry indoor environments (such as offices and warehouses), prone to rust in humid or polluted environments.
White rust appears in salt spray test: Approximately 24-48 hours (actual lifespan is significantly affected by ambient humidity and pollutants).
DX51D 100G:
Total zinc coating weight on both sides = 100 g/m² (denoted as Z100 or 100G).
Corrosion resistance improved by approximately 25%: Can withstand mildly humid environments (such as condensation in ventilation ducts and indoor environments in non-coastal areas).
White rust appears in salt spray test: Approximately 48-72 hours, over 50% longer than 80G.
3.What are the differences in substrate performance between the two?
Base Material: All are DX51D (compliant with EN 10346).
Strength: Minimum yield strength 140-300 MPa, tensile strength 270-500 MPa (non-structural, low strength).
Formability: High elongation, suitable for bending, stamping, and other processes (no difference between the two).
Surface Treatment: Both are available with glossy and fingerprint-resistant finishes.
The difference in zinc layer thickness does not affect the mechanical properties of the substrate, but an excessively thick zinc layer may increase the risk of bending cracking (100G is slightly more sensitive than 80G, but the actual impact is minimal).
4.What are the costs and cost-effectiveness of the two?
Cost: 100G steel has 25% more zinc than 80G steel, resulting in a price increase of approximately 5-8% (depending on the steel mill and order volume).
Selection Recommendation:
For applications in absolutely dry environments (such as office furniture and cabinet lining), 80G steel is more economical.
For applications subject to condensation and short-term moisture (such as ventilation ducts and kitchen appliances), 100G steel offers a more cost-effective solution (extending service life and reducing maintenance).
5.What are the scenarios where 100G is preferred?
Air conditioning ducts (especially at risk of condensation), kitchen appliance casings, and indoor metal furniture in non-coastal areas.
80G is recommended for:
Internal structural parts of home appliances, dry warehouse shelves, and internal partitions of cabinets.
Neither type is suitable for:
Outdoors, bathrooms, and coastal areas-Z180+ or pre-coated steel (e.g., DX51D+AZ180) is required.