Difference between LR DH36 and LR DH62 steel plate

LR DH36 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 355 MPa and tensile strength ranging from 490 to 620 MPa, with minimum elongation of 21% . The chemical composition features carbon ≤0.18% and manganese 0.90-1.60% . It is widely used for hull structures, offshore platforms, and shipbuilding components such as bulk carriers and container ships.

LR DH62 is an ultra-high-strength marine steel plate also certified by Lloyd's Register (LR) with impact toughness tested at -20°C . The "62" denotes a minimum yield strength of 620 MPa and tensile strength ranging from 720 to 890 MPa, with minimum elongation of 17% for thicknesses up to 100mm . Impact energy requirements are minimum 62J (longitudinal) or 41J (transverse) at -20°C . The chemical composition features carbon ≤0.20% and manganese ≤1.70%, with microalloying elements including Nb, V, Ti, Cu, Cr, Ni, and Mo . This grade requires advanced processing such as TMCP or quenching and tempering and is designed for the most critically stressed structural components in modern shipbuilding and offshore engineering, offering an exceptional strength-to-weight ratio.

Both LR DH36 and LR DH62 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 490-620 MPa, suitable for general high-strength hull construction and offshore structures, while DH62 provides a substantially higher minimum yield strength of 620 MPa with tensile strength reaching 720-890 MPa, designed for the most demanding load-bearing applications requiring maximum weight reduction . Both grades feature controlled chemical composition, but DH62 requires more advanced processing like TMCP or QT to achieve its superior mechanical properties while maintaining good weldability for critical marine service.

Chemical Composition

Mechanical Property