Difference between LR DH36 and LR DH40 steel plate

LR DH36 Steel Plate

LR DH36 is a high-strength shipbuilding steel plate certified by Lloyd's Register (LR) . The "D" grade signifies it is impact tested at -20°C . It has a minimum yield strength of 355 MPa and tensile strength ranging from 490 to 630 MPa, with minimum elongation of 21% . The chemical composition is strictly controlled with carbon ≤0.18% and manganese 0.90-1.60% . This grade is typically supplied in normalized, quenched and tempered (QT), or thermomechanical controlled processed (TMCP) conditions . It is widely used for hull construction, offshore platforms, and marine structures.

LR DH40 Steel Plate

LR DH40 is a higher-strength marine steel also certified by Lloyd's Register (LR) with impact toughness tested at -20°C . The "40" denotes a minimum yield strength of 390 MPa . It has a tensile strength ranging from 510 to 660 MPa and minimum elongation of 20% . The chemical composition includes carbon ≤0.18-0.20%, manganese 0.90-1.60%, with strict control of phosphorus and sulfur . This grade is typically supplied in normalized, quenched and tempered, or TMCP conditions . It is designed for demanding structural components in shipbuilding and offshore platforms.

Both LR DH36 and LR DH40 are LR-certified high-strength marine steels with impact toughness tested at -20°C, ensuring reliable performance in cold marine environments. Their primary difference lies in strength level: DH36 offers a minimum yield strength of 355 MPa with tensile strength of 490-630 MPa, suitable for general high-strength hull construction, while DH40 provides a higher minimum yield strength of 390 MPa with tensile strength reaching 510-660 MPa, designed for more demanding load-bearing applications. Both grades feature controlled chemical composition with carbon ≤0.18-0.20% and maintain good weldability for marine service.

Chemical Composition

Mechanical Property