What are difference between LR DH36 and LR DH42 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 is strictly controlled with carbon ≤0.18% and manganese 0.90-1.60% . This grade is widely used for hull structures, offshore platforms, and shipbuilding components such as bulk carriers and container ships.

LR DH42 is an extra-high-strength structural steel plate also certified by Lloyd's Register (LR) with impact toughness tested at -20°C . The "42" denotes a minimum yield strength of 420 MPa and tensile strength ranging from 530 to 680 MPa, with minimum elongation of 20% . The chemical composition features carbon ≤0.20% and manganese ≤1.70%, with microalloying elements for enhanced properties . This grade is designed for more demanding structural components in shipbuilding and offshore platforms requiring higher strength.

Both LR DH36 and LR DH42 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 , while DH42 provides a higher minimum yield strength of 420 MPa with tensile strength reaching 530-680 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.

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