S320GD Galvanized Steel Coil
S320GD Galvanized Steel Coil is a high-strength, hot-rolled steel with a hot-dip galvanized coating. It is primarily composed of carbon, manganese, silicon, and trace amounts of phosphorous and sulfur, providing excellent machinability and formability. With a yield strength of 320 MPa and a tensile strength ranging from 400 to 500 MPa, S320GD is well-suited for medium-load applications.
The galvanized layer of the steel coil is typically formed through the hot-dip galvanizing process. Its thickness depends on the specific application-thicker and higher-quality coatings offer better corrosion resistance. This coating significantly improves the steel coil's durability, especially in environments with high humidity or chemical exposure, making it ideal for industries like marine, chemical, and construction. In some cases, an aluminum-zinc alloy coating may be used for enhanced corrosion protection.
S320GD Galvanized Steel Coil Chemical Composition
| Element | Maximum Content (%) |
| Carbon (C) | 0.2 |
| Silicon (Si) | 0.6 |
| Manganese (Mn) | 1.7 |
| Phosphorus (P) | 0.1 |
| Sulfur (S) | 0.045 |
S320GD Galvanized Steel Coil Mecahmical Properties
| Property | Value |
| Tensile Strength (Rm) | 290 – 390 MPa |
| 0.2% Proof Strength (Rp0.2) | ≥ 320 MPa |
| Minimum Elongation (Lo = 80 mm) (A) | ≥ 17% |
Note:
The minimum elongation requirement varies with thickness:
0.5 mm < t ≤ 0.7 mm: The minimum elongation is reduced by 2% compared to the listed value.
0.35 mm < t ≤ 0.5 mm: The minimum elongation is reduced by 4% compared to the listed value.
t ≤ 0.35 mm: The minimum elongation is reduced by 7% compared to the listed value.
The tensile strength range for this grade can vary by up to 140 MPa, depending on processing conditions and coating specifications.
Available Steel Grade
|
Grade |
Yield Strength MPa≥ |
Tensile Strength MPa≥ |
Elongation A%≥ |
|
DX51D Z/ZM/AZ/AM |
240-380 |
270-500 |
22 |
|
DX52D Z/ZM/AZ/AM |
140-300 |
270-420 |
26 |
|
DX53D Z/ZM/AZ/AM |
140-260 |
270-380 |
30 |
|
DX54D Z/ZM/AZ/AM |
120-220 |
260-350 |
36 |
|
S220GD Z/ZM/AM |
220 |
300 |
20 |
|
S250GD Z/ZM/AZ/AM |
250 |
330 |
19 |
|
S280GD Z/ZM/AM |
280 |
360 |
18 |
|
S300GD A/AM |
300 |
380 |
18 |
|
S320GD Z/ZM/AM |
320 |
390 |
17 |
|
S350GD Z/ZM/AZ/AM |
350 |
420 |
16 |
|
S450GD A/AM |
450 |
480 |
15 |
|
S550GD Z/ZM/AZ/AM |
550 |
550 |
- |
FAQ:
Is Z275 enough for outdoor applications?
Yes. Z275 is suitable for most outdoor environments, including urban and rural areas. For coastal or highly corrosive environments, higher zinc coatings may be recommended.
What is the difference between S320GD and lower-grade galvanized steel?
S320GD offers higher yield strength and better load-bearing capacity while maintaining good formability and corrosion resistance.
Can S320GD galvanized steel be welded?
Yes. S320GD can be welded using standard welding methods, but proper ventilation and surface preparation are recommended due to the zinc coating.
Is S320GD suitable for cold forming?
Yes. S320GD has good formability and is suitable for roll forming, bending, and cold shaping processes.
What thickness range is available for S320GD galvanized steel?
S320GD galvanized steel is commonly available from thin gauges (around 0.35 mm) up to structural thicknesses of 6.0 mm or more, depending on supply capability.
What surface finishes are available for S320GD galvanized steel?
Typical surface finishes include regular spangle, minimized spangle, and zero spangle, depending on application requirements.
How long does S320GD+Z275 galvanized steel last?
In normal environments, S320GD+Z275 can provide corrosion protection for 15–30 years, depending on exposure conditions.
