Difference between LR AH32 and LR AH62 steel plate

LR AH32 is a higher-strength structural steel plate certified by Lloyd's Register (LR) for shipbuilding and marine applications . The "A" grade signifies it is impact tested at 0°C. It has a minimum yield strength of 315 MPa and tensile strength ranging from 440 to 590 MPa . Minimum elongation is 22% . The chemical composition features carbon ≤0.18% and manganese 0.90-1.60% . This grade is widely used for hull structures, offshore platforms, and general shipbuilding components.

LR AH62 is an ultra-high-strength marine steel plate also certified by Lloyd's Register (LR) with impact toughness tested at 0°C . The "62" denotes a minimum yield strength of 440 MPa and tensile strength ranging from 620 to 800 MPa, with minimum elongation of 19% . The chemical composition is more complex than AH32, with carbon ≤0.18%, manganese 0.90-1.60%, and additional alloying elements including nickel (0.70-1.80%), chromium (0.40-1.60%), and molybdenum (≤0.70%) to achieve its superior mechanical properties. This grade is delivered in normalized or quenched and tempered conditions and is designed for demanding structural components in shipbuilding and offshore structures requiring maximum strength-to-weight ratio.

Both LR AH32 and LR AH62 are LR-certified high-strength marine steels with impact toughness tested at 0°C. Their primary difference lies in strength level: AH32 offers a minimum yield strength of 315 MPa with tensile strength of 440-590 MPa, suitable for general high-strength hull construction, while AH62 provides a substantially higher minimum yield strength of 440 MPa with tensile strength reaching 620-800 MPa, designed for more demanding load-bearing applications requiring superior strength. Both grades feature controlled chemical composition, but AH62 requires more complex alloying and advanced processing like quenching and tempering to achieve its enhanced mechanical properties while maintaining good weldability for critical marine service.

Chemical Composition

Mechanical Property