LR EH40 vs LR EH42

LR EH40 is a high-strength marine steel plate certified by Lloyd's Register (LR) for shipbuilding and offshore applications. The "EH" designation signifies it is impact tested at -40°C, ensuring excellent toughness for vessels operating in cold environments such as Arctic waters . It has a minimum yield strength of 390 MPa and tensile strength ranging from 510 to 650 MPa, with minimum elongation of 20% for thicknesses up to 100mm . 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 critical marine components.

LR EH42 is an extra-high-strength marine steel plate also certified by Lloyd's Register (LR), with impact toughness tested at -40°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% for thicknesses up to 100mm . Impact energy requirements are minimum 28J (transverse) or 42J (longitudinal) at -40°C . The chemical composition features carbon ≤0.20% and manganese ≤1.70% . This grade is designed for more demanding structural applications in shipbuilding and offshore platforms requiring superior strength.

Both LR EH40 and LR EH42 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: EH40 offers a minimum yield strength of 390 MPa with tensile strength of 510-650 MPa, suitable for general high-strength hull construction and offshore structures , while EH42 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, with EH42 typically requiring more advanced processing to achieve its enhanced mechanical properties.

Chemical Composition

Mechanical Property