1. Material Classification and Standards
Standard Definition
A283 Gr.B is the carbon structural steel plate in the ASTM A283/A283M standard, which belongs to the medium-low strength grade, and is suitable for general structural fields such as buildings, bridges, and so on.
According to quality, it is divided into four grades: Gr.A, Gr.B, Gr.C, and Gr.D. Among them, the strength of Gr.B is higher than that of Gr.A and lower than that of Gr.C and Gr.D. The strength of Gr.B is higher than that of Gr.A, and lower than that of Gr.C and Gr.D.
Manufacturing Process
It is smelted in flat furnaces, alkaline oxygen converters, or electric furnaces, and delivered as hot rolled or normalized.
2. chemical composition
| elements | C | Si | Mn | P | S |
|---|---|---|---|---|---|
| content | ≤0.20% | 0.15%~0.40% | 0.90%~1.30% | ≤0.035% | ≤0.035% |
Low carbon design: low carbon content (less than or equal to 0.20%) ensures good weldability and cold working performance.
Manganese reinforcement: higher manganese content (0.90% to 1.30%) enhances material strength and toughness.
3. mechanical property
| Terms | yield strength(≥) | tensile strength(≥) | elongation(≥) |
|---|---|---|---|
| numerical | 245 MPa | 310 MPa | 24% |
Medium-low strength characteristics: suitable for non-high-pressure scenarios (e.g. building frames, guardrails, etc.).
High ductility: elongation of at least 24%, supporting stamping, bending, and other processing techniques.
4. Applications
Construction field: bridge support structures, building frames, storage racks, etc.
Engineering structure: welded round pipes for road guardrails (e.g., DN350 galvanized welded pipes), low-pressure vessel parts.
General manufacturing: mechanical parts, non-load-bearing parts of ships, etc.
5. Comparison with other grades
| Grade | yield strength(MPa) | tensile strength(MPa) | Applications |
|---|---|---|---|
| Gr.A | ≥165 | 310~415 | Light duty structures (e.g., supports, fences) |
| Gr.B | ≥245 | ≥310 | Medium loads (bridges, buildings) |
| Gr.C | ≥275 | ≥345 | Heavy-duty structures (pressure vessels, power stations) |
