Difference between LR DH32 and LR DH40 steel plate

LR DH32 is a higher-strength structural steel plate certified by Lloyd's Register (LR) for shipbuilding and marine applications . The "D" grade signifies it is impact tested at -20°C . It has a minimum yield strength of 315 MPa (46 ksi) and tensile strength ranging from 440 to 590 MPa (64-83 ksi) . Minimum elongation is 22% . The chemical composition features carbon ≤0.18% and manganese 0.90-1.60% . This grade is typically supplied in normalized or controlled rolled conditions and is widely used for hull structures and general shipbuilding components .

LR DH40 is a higher-strength marine steel plate also certified by Lloyd's Register (LR) with impact toughness tested at -20°C . The "40" denotes a minimum yield strength of 390 MPa and tensile strength ranging from 510 to 660 MPa . Minimum elongation is 20% . The chemical composition features carbon ≤0.18% and manganese 0.90-1.60% . This grade is typically supplied in normalized, quenched and tempered, or TMCP conditions and is designed for demanding structural components in shipbuilding, including large bulk carriers and oil tankers.

Both LR DH32 and LR DH40 are LR-certified higher-strength marine steels with impact toughness tested at -20°C, ensuring reliable performance in cold marine environments . Their primary difference lies in strength level: DH32 offers a minimum yield strength of 315 MPa with tensile strength of 440-590 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 requiring superior strength. Both grades feature controlled chemical composition and maintain good weldability for critical marine service.

Chemical Composition

Mechanical Property