JIS G3125 SPA-H is one of the core products of our company. In addition to supplying high-quality SPA-H weathering steel at competitive prices, we also provide comprehensive technical support to help customers resolve all kinds of material-related questions.
Meanwhile, we offer value-added processing services for JIS G3125 SPA-H steel, including cutting, bending, welding, drilling, and other fabrication processes, enabling customers to receive ready-to-use materials for their projects.
Chemical Composition Comparison
| Standard | Grade | Chemical Elements (wt.%) | Typical Application |
|---|---|---|---|
| Q/ASB 2 | SPA-H | C 0.0500–0.1200, Cr 0.3000–1.2500, Cu 0.2500–0.5000, Mn 0.2000–0.6000, Ni ≤ 0.6500, P 0.0700–0.1200, S ≤ 0.0250, Si 0.2500–0.7500 | Hot rolled steel sheet and strip for containers |
| KS D 3542 | SPA-H | C ≤ 0.1200, Cr 0.3000–1.2500, Cu 0.2500–0.5500, Mn ≤ 0.6000, Ni ≤ 0.6500, P 0.0700–0.1500, S ≤ 0.0350, Si 0.2500–0.7500 | High-performance weather-resistant hot rolled steel |
| Q/SGZGS 331 | SPA-H | C ≤ 0.1200, Cr 0.3000–1.2500, Cu 0.2500–0.5500, Mn ≤ 0.6000, Ni ≤ 0.6500, P 0.0700–0.1500, S ≤ 0.0350, Si 0.2000–0.7500 | Hot rolled steel sheet and strip for containers |
| Q/TGF 340 | SPA-H | C ≤ 0.1200, Cr 0.3000–1.2500, Cu 0.2500–0.5500, Mn ≤ 0.6000, Ni ≤ 0.6500, P 0.0700–0.1500, S ≤ 0.0300, Si 0.2000–0.7500 | Hot rolled steel strip for corrosion-resistant structures |
Mechanical Properties Comparison
| Standard | Grade | Yield Strength Rp0.2 (MPa) | Tensile Strength Rm (MPa) | Impact KV/Ku (J) | Elongation A (%) | Reduction of Area Z (%) | Heat Treatment Condition | Hardness (HBW) |
|---|---|---|---|---|---|---|---|---|
| JIS G3125 | SPA-H | ≥ 318 | ≥ 937 | 21 | 13 | 33 | Solution & Aging, Annealing, Ausaging, Q+T | 432 |
| Q/ASB 2 | SPA-H | ≥ 377 | ≥ 826 | 44 | 12 | 22 | Solution & Aging, Annealing, Ausaging, Q+T | 323 |
| KS D 3542 | SPA-H | ≥ 366 | ≥ 838 | 22 | 41 | 23 | Solution & Aging, Annealing, Ausaging, Q+T | 314 |
| Q/SGZGS 331 | SPA-H | ≥ 424 | ≥ 847 | 23 | 43 | 42 | Solution & Aging, Annealing, Ausaging, Q+T | 322 |
| Q/TGF 340 | SPA-H | ≥ 163 | ≥ 965 | 24 | 24 | 31 | Solution & Aging, Annealing, Ausaging, Q+T | 432 |
| TIS 2011-2543 | SPA-H | ≥ 118 | ≥ 539 | 41 | 21 | 32 | Solution & Aging, Annealing, Ausaging, Q+T | 123 |
JIS G3125 SPA-H Equivalent Physical Properties Comparison
Japan – JIS G3125 SPA-H
Thermal conductivity (W/m·°C): approx. 34.3
Density: approx. 7.81 g/cm³
Electrical resistivity (Ω·mm²/m): approx. 0.12
China – Q/ASB 2 SPA-H
Thermal conductivity (W/m·°C): approx. 23.3
Density: approx. 7.65 g/cm³
Electrical resistivity (Ω·mm²/m): approx. 0.21
Korea – KS D 3542 SPA-H
Thermal conductivity (W/m·°C): approx. 13.3
Density: approx. 7.32 g/cm³
Electrical resistivity (Ω·mm²/m): approx. 0.42
China – Q/SGZGS 331 SPA-H
Thermal conductivity (W/m·°C): approx. 12.3
Density: approx. 7.63 g/cm³
Electrical resistivity (Ω·mm²/m): approx. 0.11
China – Q/TGF 340 SPA-H
Thermal conductivity (W/m·°C): approx. 21.3
Density: approx. 7.26 g/cm³
Electrical resistivity (Ω·mm²/m): approx. 0.44
Thailand – TIS 2011-2543 SPA-H
Thermal conductivity (W/m·°C): approx. 31.3
Density: approx. 7.51 g/cm³
Electrical resistivity (Ω·mm²/m): approx. 0.41
Q1: What is SPA-H Corten steel?
SPA-H is a Japanese standard weathering steel grade specified in JIS G 3125. It contains alloying elements such as copper, chromium, and nickel, which allow it to form a dense protective rust layer on the surface. This patina significantly slows down further corrosion and improves long-term durability in atmospheric environments.
Q2: What are the main advantages of SPA-H weathering steel?
The key advantages of SPA-H steel include excellent atmospheric corrosion resistance, high strength, and low maintenance cost. Unlike ordinary carbon steel, SPA-H does not require frequent painting or coating, which helps reduce lifecycle costs while maintaining a unique natural appearance.
Q3: Where is SPA-H Corten steel commonly used?
SPA-H steel is widely used in bridges, building structures, architectural façades, railway carriages, containers, air preheaters, and economizers. It is especially suitable for outdoor structures exposed to changing weather conditions for long periods.
Q4: Does SPA-H steel need painting or surface treatment?
In most outdoor applications, no additional painting is required. SPA-H naturally forms a stable rust layer after exposure to the atmosphere. However, in highly corrosive environments (such as marine or high-salt areas), additional surface protection may be recommended to extend service life.
Q5: How long does it take for SPA-H steel to form a stable patina?
Under normal atmospheric conditions, SPA-H steel typically forms a stable protective patina within 6 to 24 months
