Hot-dip Galvanized Structural Steel
Hot-dip galvanized steel S250GD in accordance with the EN 10346 standard is a high-quality structural steel that has been specially developed for use in the construction industry. With the material number 1.0242, S250GD has a minimum yield strength Rp0.2 of 250 N/mm² and is therefore classified in the medium strength classes of hot-dip galvanized structural steels. The EN 10346 standard not only specifies the chemical composition and mechanical properties, but also defines the hot-dip galvanizing process that creates a uniformly protective zinc coating on the steel surface. The available coatings +Z, +ZF, +ZA, +ZM, +AZ and +AS enable precise adaptation to different environmental conditions and load scenarios.
S250GD+Z,S250GD+AZ, S250GD+ZM
| Property | S250GD+Z | S250GD+AZ (Galvalume) | S250GD+ZM (ZAM) |
| Coating | Pure Zinc | 55% Al-43.4% Zn-1.6% Si | Zn + Mg/Al (e.g., ZM310) |
| Corrosion | Good | Excellent | Outstanding |
| Heat Resistance | Moderate | Excellent | High |
| Appearance | Zinc-spangled | Silvery spangled | Dark gray uniform |
| Formability | Excellent | Good (coating harder) | Good (high toughness) |
| Cost | Low | Medium | High |
| Uses | General structures | Roofs, ducts, appliances | Marine, harsh environments |
DIN S250GD + Z Chemical element
DIN S250GD + Z DIN EN 10326 in addition to carbon, steel also contains a small amount of manganese (Mn), silicon (Si), sulfur (S), phosphorus (P), oxygen (O), nitrogen (N) and hydrogen (H). These elements are not intentionally added to improve the quality of steel, but are brought in by ore and smelting process, so they are called impurity elements. These impurities have a certain impact on the properties of steel. In order to ensure the quality of steel, the chemical composition of all kinds of steel is strictly stipulated in technical standards.
The main elements proportion is as below:
| Element | Min | Max | Similar |
|---|---|---|---|
| Si | - | 0.6000 | - |
| S | - | 0.0450 | - |
| P | - | 0.1000 | - |
| Mn | - | 1.7000 | - |
| C | - | 0.2000 | - |
DIN S250GD + Z Mechanical properties
| Yield Rp0.2 (MPa) |
Tensile Rm (MPa) |
Impact KV/Ku (J) |
Elongation A (%) |
Reduction in cross section on fracture Z (%) |
As-Heat-Treated Condition | Brinell hardness (HBW) |
|---|---|---|---|---|---|---|
| 998 (≥) | 825 (≥) | 11 | 14 | 14 | Solution and Aging, Annealing, Ausaging, Q+T,etc | 122 |
Mechanical properties
| Steel grade | Yield strength ReH or Rp0,2 transverse | Tensile strength Rm transverse | Fracture elongation A80 transverse* |
| MPa | MPa | % | |
| S220GD | ≥ 220 | ≥ 300 | ≥ 20 |
| S250GD | ≥ 250 | ≥ 330 | ≥ 19 |
| S280GD | ≥ 280 | ≥ 360 | ≥ 18 |
| S320GD | ≥ 320 | ≥ 390 | ≥ 17 |
| S350GD | ≥ 350 | ≥ 420 | ≥ 16 |
| S390GD | ≥ 390 | ≥ 460 | ≥ 16 |
| S420GD | ≥ 420 | ≥ 480 | ≥ 15 |
| S550GD | ≥ 550 | ≥ 560 | - |
1) range: 140 MPa (benchmark)
2) thickness ≥ 0,71 mm (≤ 0,70 minus two units)
Surface finish
| Steel grade | NA | MA | MB | MC* |
| Thickness range | ||||
| mm | mm | mm | mm | |
| S220GD | 0.40 - 4.00 | 0.40 - 4.00 | 0.40 - 4.00 | 0.40 - 2.00 |
| S250GD | 0.40 - 4.00 | 0.40 - 4.00 | 0.40 - 4.00 | 0.40 - 2.00 |
| S280GD | 0.40* - 4.00 | 0.40* - 4.00 | 0.40* - 4.00 | 0.40* - 2.00 |
| S320GD | 0.50 - 4.00 | 0.50 - 4.00 | 0.50 - 4.00 | 0.50 - 2.00 |
| S350GD | 0.50 - 3.00 | 0.50 - 3.00 | 0.50 - 3.00 | 0.50 - 2.00 |
| S390GD | - | 0.50 - 2.50 | - | - |
| S420GD | - | 0.50 - 2.50 | - | - |
| S550GD | - | 2.00 - 3.00 | - | - |
* Lieferung nach Vereinbarung
FAQ:
Q: What is the chemical composition of S250GD steel?
A: The chemical composition of S250GD steel typically includes carbon, manganese, phosphorus, sulfur, and a zinc coating. The specific composition balances strength, ductility, and corrosion resistance.
Q: What is the minimum yield strength of S250GD steel?
A: The minimum yield strength of S250GD steel is 250 MPa. This property ensures the steel can withstand significant stress and strain without deforming, making it a reliable choice for structural applications.
Q: How is the thickness of the steel sheet relevant to its application?
A: The thickness of the steel sheet affects its strength, weight, and flexibility. Thicker sheets offer more strength and are used in heavy-duty applications, while thinner sheets are lighter and used in applications where weight is a concern, such as automotive parts.
Q: Can S250GD steel be welded?
A: Yes, S250GD steel can be welded. However, appropriate welding techniques are important to maintain the integrity of the galvanized coating and prevent corrosion at the weld joints.
Q: What standards govern the production of S250GD galvanized steel?
A: The production of S250GD galvanized steel is governed by ASTM and EN standards, which ensure consistent quality, thickness, and properties across different batches and manufacturers.
