Difference between LR EH36 and LR EH50 steel plate

LR EH36 is a high-strength shipbuilding steel plate certified by Lloyd's Register (LR) . The "EH" designation signifies it is impact tested at -40°C, ensuring excellent toughness for cold-environment applications such as Arctic operations . It has a minimum yield strength of 355 MPa (51 ksi) and tensile strength ranging from 490 to 620 MPa (71-90 ksi) . Minimum elongation is 21-22% depending on thickness . The chemical composition is strictly controlled with carbon ≤0.18% and manganese 0.90-1.60% . This grade is widely used for hull construction, offshore platforms, decks, and critical structural components of vessels operating in harsh marine conditions .

LR EH50 is an extra-high-strength marine steel plate also certified by Lloyd's Register (LR) with impact toughness tested at -40°C . The "50" denotes a minimum yield strength of 500 MPa . It has a higher tensile strength ranging from 610 to 770 MPa and minimum elongation of 18% for thicknesses up to 100mm . Impact energy requirements are minimum 50J (longitudinal) or 33J (transverse) at -40°C . The chemical composition features carbon ≤0.20%, manganese ≤1.70%, with microalloying elements including Nb, V, and Ti . This grade is designed for demanding structural components in shipbuilding, offshore platforms, and marine structures requiring superior strength-to-weight ratio .

Both LR EH36 and LR EH50 are LR-certified high-strength marine steels with excellent low-temperature toughness tested at -40°C, ensuring reliable performance in harsh marine environments including Arctic conditions . Their primary difference lies in strength level: EH36 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 EH50 provides a substantially higher minimum yield strength of 500 MPa with tensile strength reaching 610-770 MPa, designed for more demanding load-bearing applications requiring superior strength. Both grades feature controlled chemical composition and require advanced processing like TMCP or normalized rolling to achieve their mechanical properties while maintaining good weldability for critical marine service.

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Mechanical Property