Q：What are the common types of galvanized coils?
A：European standard common models:DC51D-Z,DC53D-Z,DX51D-Z/ZF
Common models of Japanese Standard (JIS)：SGCC,SGCD
Common Models of American Standard (ASTM):G90,A653 SS Grade 33
Q:What do Q235B and Q345B stand for?
A:Q235B: Q: The first letter of the pinyin of the steel yield strength "Qu";
235: Yield strength ≥ 235MPa (at room temperature);
B: Quality grade (Grade B means that the impact performance at room temperature is qualified).
Q345B: Q: Same as above;
345: Yield strength ≥ 345MPa (at room temperature);
B: Quality grade (same grade as Q235B, but with higher actual performance).
Q：What is the difference between Q235B and Q345B?
A：Strength difference: Q345B is about 50% stronger than Q235B, and can reduce the amount of material used under the same load (thinner and lighter).
Alloy VS Carbon steel: Q345B adds alloys such as manganese and vanadium to improve strength and low-temperature performance; Q235B is pure carbon steel with low cost.
Applicable environment: Q345B (low-temperature resistant) is selected for open-air projects in the north, and Q235B is more economical for ordinary buildings in the south.
Q：What is the difference between hot-dip galvanizing (Z) and electrogalvanizing (ZF)?
A：1. Different processes: Hot-dip galvanizing is to immerse steel in molten zinc liquid (about 450℃) for galvanizing, while electro-galvanizing is galvanizing at room temperature by electrolysis.
2. Zinc layer thickness: Hot-dip galvanizing layer is thicker (generally 20-300g/m²), while electro-galvanizing layer is thinner (generally 3-20g/m²).
3. Appearance difference: There are zinc flowers on the surface of hot-dip galvanizing, while the surface of electro-galvanizing is uniform, smooth and free of zinc flowers.
4. Corrosion resistance: Hot-dip galvanizing has better anti-corrosion performance and is suitable for outdoor use; electro-galvanizing has weaker anti-corrosion performance and usually needs to be used in conjunction with other coatings.
5. Application areas: Hot-dip galvanizing is mostly used in outdoor projects such as buildings and bridges, while electro-galvanizing is mainly used in home appliances, electronics and other products that require fine surfaces.
6. Cost difference: The production cost of hot-dip galvanizing is lower, while the cost of electro-galvanizing is relatively higher.
Q:How do different zinc layer weights (such as Z60, Z120) affect the usage scenario?
A:The weight of the zinc layer of the galvanized coil directly affects its corrosion resistance and usage scenarios. The main differences are as follows:
1. Z60 (60g/m² on both sides)
Corrosion resistance: medium, suitable for ordinary environments
Typical uses: indoor home appliance housings, cable trays, ventilation ducts
Advantages: low cost, meets basic anti-rust needs
Service life: generally 5-10 years
2. Z120 (120g/m² on both sides)
Corrosion resistance: strong, suitable for outdoor environments
Typical uses: building roofs, steel structures, outdoor guardrails
Advantages: good corrosion resistance, suitable for rainy areas
Service life: up to 15-25 years
Selection suggestions:
Z60 is more economical for ordinary indoor environments;Z120 is the most cost-effective for general outdoor use.
The thicker the zinc layer, the higher the price, and the cost and usage needs need to be balanced.