ASTM A131/A131M — Marine structural steel
Grades
普通强度: A, B, D, E; 高强度: AH32, DH32, EH32, FH32, AH36, DH36, EH36, FH36, AH40, DH40, EH40, FH40
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| D | C≤0.21, Mn≥0.60(>25mm), P≤0.035, S≤0.035 | Rm 400-520 MPa, Rp0.2 ≥235 MPa, A≥22%, quenching and tempering |
| E | C≤0.18, Mn≥0.70, P≤0.035, S≤0.035, Al≥0.015 | Rm 400-520 MPa, Rp0.2 ≥235 MPa, A≥22%, Akv≥27J at -40℃, quenching and tempering |
| AH32 | C≤0.18, Mn 0.70-1.60, Si 0.10-0.50, P≤0.030, S≤0.030, Nb 0.005-0.05, V 0.02-0.10, Ti≤0.02, Cu≤0.35, Cr≤0.20, Ni≤0.40, Mo≤0.08, N≤0.012 | Rm 440-590 MPa, Rp0.2 ≥315 MPa, A≥22%, Akv≥31J at 0℃, TMCP/normalizing |
Application scope
ASTM A131/A131M specifies structural steel plates for shipbuilding, divided into two main series: ordinary strength and high strength, with grades including A, B, D, E and AH, DH, EH, FH. The standard specifies chemical composition, tensile strength, and low-temperature impact requirements. Delivery is available in hot-rolled, normalized, or TMCP conditions. It exhibits good weldability and low-temperature toughness, is approved by the relevant classification society, and is suitable for primarily welded load-bearing hull components.
Typical applications
Widely used in major load-bearing structures such as hull shells, decks, bottom plates, side plates, and transverse bulkheads, as well as in offshore platform components and ship skeletons. The standard strength grade is suitable for general hull parts, while the high strength grade is used for weight reduction and high-stress areas. With its good weldability and low-temperature toughness, it is suitable for various types of ships and marine structures that rely primarily on welded assembly and must meet classification society requirements.
