Products Description
JIS G3125 SPA-H Low Alloy Weathering Resistant Steel Sheet is designed for applications where corrosion resistance is critical, particularly in environments exposed to moisture and varying weather conditions.
Its most significant characteristics include high tensile strength, good weldability, and the ability to withstand harsh weather without significant degradation.
The inherent properties of SPA H Steel make it an ideal choice for structures such as bridges, buildings, and other outdoor installations.
Chemical Composition
| Element (Symbol and Name) | Percentage Range (%) |
|---|---|
| C (Carbon) | 0.12 - 0.20 |
| Mn (Manganese) | 0.50 - 1.50 |
| P (Phosphorus) | ≤ 0.04 |
| S (Sulfur) | ≤ 0.03 |
| Cu (Copper) | 0.25 - 0.55 |
| Cr (Chromium) | 0.20 - 0.50 |
| Ni (Nickel) | 0.30 - 0.50 |
Mechanical Properties
| Property | Condition/Temper | Test Temperature | Typical Value/Range (Metric) | Typical Value/Range (Imperial) | Reference Standard for Test Method |
|---|---|---|---|---|---|
| Tensile Strength | As Rolled | Room Temp | 490 - 620 MPa | 71 - 90 ksi | ASTM E8 |
| Yield Strength (0.2% offset) | As Rolled | Room Temp | 355 - 450 MPa | 51 - 65 ksi | ASTM E8 |
| Elongation | As Rolled | Room Temp | 20 - 25% | 20 - 25% | ASTM E8 |
| Hardness (Brinell) | As Rolled | Room Temp | 150 - 200 HB | 150 - 200 HB | ASTM E10 |
| Impact Strength (Charpy) | -40°C | -40°C | 27 J | 20 ft-lbf | ASTM E23 |
Heat Resistance
| Property/Limit | Temperature (°C) | Temperature (°F) | Remarks |
|---|---|---|---|
| Max Continuous Service Temp | 400 °C | 752 °F | Suitable for structural applications |
| Max Intermittent Service Temp | 450 °C | 842 °F | Short-term exposure only |
| Scaling Temperature | 500 °C | 932 °F | Risk of oxidation at high temps |
Applications
Bridge Structures
SPA-H weathering steel plates are widely used in the construction of bridges and other structural components. With a yield strength of ≥355 MPa and tensile strength ranging from 490–630 MPa, they can withstand complex loads and harsh climatic conditions. Compared to ordinary carbon steel, SPA-H can reduce maintenance costs by 30%–50% in long-term outdoor applications, making it ideal for sea-crossing bridges and highway bridges.
Containers and Storage Tanks
Thanks to their excellent weather and corrosion resistance, SPA-H plates are widely applied in containers, storage tanks, and other storage equipment. Their atmospheric corrosion resistance is about 2–8 times higher than that of ordinary carbon steel, extending service life by 15–20 years. This makes them especially suitable for petroleum tanks, chemical containers, and shipping containers.
Vehicle Components
SPA-H weathering steel plates are used to manufacture structural parts for cars, trains, and ships. For example, when applied to railway cars, SPA-H can reduce body weight by 10%–15%, improving durability and lowering fuel consumption. Its excellent fatigue resistance also ensures long-term operational safety.
Building Exterior Decoration
Due to its distinctive rust-like appearance and self-protective weathering properties, SPA-H is popular in exterior walls, facades, and landscape decoration. After several months of atmospheric exposure, the surface develops a stable rust layer of about 0.5–1.5 mm thickness, effectively preventing further corrosion. Many modern landmarks, such as office towers and cultural centers, use SPA-H plates for both aesthetic and functional purposes.
Construction Machinery
In the field of construction machinery, SPA-H weathering steel plates are suitable for manufacturing components of excavators, loaders, and cranes. With high yield strength and excellent impact toughness, they maintain performance even in environments as low as -20°C. Compared with conventional steels, machinery made with SPA-H plates can achieve a service life increase of over 25%
