Difference between LR EH36 and LR EH55 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 and tensile strength ranging from 490 to 630 MPa . Minimum elongation is 21% . 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, and critical structural components of vessels operating in harsh marine conditions .

LR EH55 is an ultra-high-strength marine steel plate also certified by Lloyd's Register (LR) with impact toughness tested at -40°C . The "55" denotes a minimum yield strength of 550 MPa and tensile strength ranging from 670 to 830 MPa, with minimum elongation of 18% for thicknesses up to 100mm . Impact energy requirements are minimum 55J (longitudinal) or 37J (transverse) at -40°C . The chemical composition features carbon ≤0.20%, manganese ≤1.70%, with microalloying elements including Nb and V . This grade is designed for critical, highly stressed structural members in shipbuilding and demanding offshore applications .

Both LR EH36 and LR EH55 are LR-certified high-strength marine steels with excellent low-temperature toughness tested at -40°C, ensuring reliable performance in harsh marine environments. Their primary difference lies in strength level: EH36 offers a minimum yield strength of 355 MPa with tensile strength of 490-630 MPa, suitable for general high-strength hull construction and offshore structures, while EH55 provides a substantially higher minimum yield strength of 550 MPa with tensile strength reaching 670-830 MPa, designed for more demanding load-bearing applications requiring superior strength. Both grades feature controlled chemical composition, with EH55 typically requiring more advanced processing to achieve its enhanced mechanical properties while maintaining good weldability for critical marine service.

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Mechanical Property