Difference between ABS FH32 and ABS FH40 steel plate

ABS FH32 is a high-strength marine steel plate certified by the American Bureau of Shipping (ABS) for shipbuilding and offshore applications . The "F" grade signifies it is impact tested at the extremely low temperature of -60°C, ensuring exceptional toughness for vessels operating in polar and Arctic environments . It has a minimum yield strength of 315 MPa and a tensile strength ranging from 440 to 590 MPa, with a minimum elongation of 22% . The chemical composition is strictly controlled with carbon ≤0.16% and manganese 0.90-1.60% . This grade is widely used for hull structures, offshore platforms, and ice-class vessels requiring superior low-temperature performance .

ABS FH40 is a higher-strength marine steel plate also certified by ABS, manufactured through quenching and tempering or thermo-mechanical control processing (TMCP) . Like FH32, it is impact tested at -60°C, with minimum impact energy requirements of 26J (transverse) and 39J (longitudinal) for standard thicknesses . The "40" denotes a minimum yield strength of 390 MPa and a tensile strength ranging from 510 to 660 MPa, with a minimum elongation of 20% . Its chemical composition is similar to FH32 with carbon ≤0.16% and manganese 0.90-1.60%, but may contain slightly different microalloying levels . This grade is designed for demanding structural applications in large vessels, offshore drilling units, and critical marine structures requiring superior strength-to-weight ratio .

Both ABS FH32 and ABS FH40 are ABS-certified high-strength marine steels with exceptional low-temperature toughness tested at -60°C, ensuring reliable performance in the most extreme Arctic and harsh marine environments . Their primary difference lies in strength level: FH32 offers a minimum yield strength of 315 MPa with tensile strength of 440-590 MPa, suitable for general high-strength hull construction and secondary structures, while FH40 provides a higher minimum yield strength of 390 MPa with tensile strength reaching 510-660 MPa, designed for more demanding load-bearing applications requiring superior strength . Both grades feature strictly controlled chemical composition with carbon ≤0.16% and maintain good weldability for critical marine service, making them ideal for icebreakers, offshore platforms, and vessels operating in polar regions.

Chemical Composition

Mechanical Property