Detailed introduction of St37-2 steel plate and its applications in industry

Detailed introduction of St37-2 steel plate and its applications in industry

Below is a detailed English introduction to the St37-2 steel plate, including its chemical composition and properties presented in tables.

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Detailed Introduction to St37-2 Steel Plate

St37-2 is a widely used low-carbon structural steel grade specified under the German standard DIN 17100. Known for its versatility and cost-effectiveness, this steel is commonly employed in construction, engineering, and manufacturing industries. St37-2 belongs to the category of non-alloy structural steels, characterized by its moderate strength, good weldability, and excellent ductility. Its designation, "St37-2," indicates a minimum yield strength of approximately 235 MPa (for thicknesses up to 16 mm), making it suitable for applications where high strength is not the primary requirement but reliability and ease of fabrication are essential.

The steel’s composition is carefully controlled to ensure consistent mechanical properties and performance in structural applications. With a low carbon content (typically up to 0.20%), St37-2 exhibits good formability and machinability, allowing it to be shaped, bent, or welded with relative ease. This makes it an ideal choice for producing structural components such as beams, columns, plates, and angles used in buildings, bridges, and machinery. Additionally, St37-2 is often delivered in a hot-rolled condition, which enhances its surface quality and dimensional accuracy.

St37-2 is equivalent to several international standards, including S235JR under the European standard EN 10025-2 and ASTM A36 in the United States, although slight differences in composition and properties may exist. Its widespread use is attributed to its balanced combination of strength, toughness, and affordability, though it lacks significant corrosion resistance compared to alloyed or stainless steels. To mitigate this, surface treatments such as galvanizing or painting are often applied to enhance durability in corrosive environments.

The mechanical properties of St37-2, such as yield strength, tensile strength, and elongation, vary slightly depending on the thickness of the plate, as specified in DIN 17100. These properties ensure that the steel can withstand moderate loads and stresses, making it a reliable material for general-purpose structural applications. Below, the chemical composition and mechanical properties of St37-2 are detailed in tabular form for clarity.

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Chemical Composition of St37-2 Steel Plate
The chemical composition is based on ladle analysis as per DIN 17100 and may slightly vary depending on the manufacturer or product analysis. The following table represents the maximum allowable percentages of key elements:

| Element         | Symbol | Maximum Content (%) |
|-----------------|--------|---------------------|
| Carbon          | C      | 0.20                |
| Manganese       | Mn     | 1.40                |
| Phosphorus      | P      | 0.045               |
| Sulfur          | S      | 0.045               |
| Silicon         | Si     | Not specified       |
| Nitrogen        | N      | 0.009 (if specified)|

Notes:
- Silicon (Si) content is not explicitly limited in the standard but is typically low in St37-2.
- Nitrogen content is controlled only when specified in the order, particularly for improved weldability.

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Mechanical Properties of St37-2 Steel Plate
The mechanical properties of St37-2 depend on the thickness of the plate and are tested under standard conditions as per DIN 17100. The table below provides typical values:

| Property                | Thickness (mm) | Value                |
|-------------------------|----------------|----------------------|
| Yield Strength (ReH)    | ≤ 16           | ≥ 235 MPa           |
|                         | 16–40          | ≥ 225 MPa           |
|                         | 40–63          | ≥ 215 MPa           |
| Tensile Strength (Rm)   | All thicknesses| 360–510 MPa         |
| Elongation (A)          | ≤ 16           | ≥ 25% (longitudinal)|
|                         | 16–40          | ≥ 24% (longitudinal)|
|                         | 40–63          | ≥ 23% (longitudinal)|

Notes:
- Yield strength decreases slightly as the thickness increases due to the steel’s microstructural changes during rolling.
- Elongation values are based on longitudinal test specimens; transverse values may differ slightly.
- Impact resistance is not typically specified for St37-2 unless additional testing (e.g., low-temperature impact) is requested.

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Applications and Advantages
St37-2 steel plates are extensively used in civil and industrial engineering projects. Common applications include the construction of bridges, buildings, shipbuilding, and storage tanks. Its ability to be riveted, bolted, or welded makes it highly adaptable to various fabrication methods. Furthermore, St37-2’s moderate strength and ductility allow it to be employed in automotive components and general machinery where weight reduction is a consideration.

The primary advantages of St37-2 include its affordability, ease of processing, and availability in large quantities. It is often supplied with mill test certificates that detail its chemical composition and mechanical properties, ensuring compliance with DIN 17100 standards. However, its susceptibility to rust requires protective measures in outdoor or humid environments.

Conclusion
St37-2 steel plate remains a cornerstone material in structural engineering due to its reliable performance, versatility, and economic value. Its well-defined chemical composition and mechanical properties make it a trusted choice for a wide range of applications, particularly where cost and ease of fabrication are critical factors. By understanding its characteristics, engineers and manufacturers can optimize its use in projects while addressing its limitations, such as corrosion resistance, through appropriate treatments.

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This introduction provides a comprehensive overview of St37-2 steel plate, with its chemical composition and properties clearly presented in tables as requested. Let me know if you need further adjustments or additional details!