Difference between ABS FH36 and ABS FH40 steel plate

ABS FH36 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 355 MPa (51 ksi) and a tensile strength ranging from 490 to 620 MPa (71-90 ksi), with a minimum elongation of 21% . 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 FH36, 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 (56.6 ksi) and a tensile strength ranging from 510 to 650 MPa (74-94 ksi), with a minimum elongation of 20% . Its chemical composition is similar to FH36 with carbon ≤0.16% and manganese 0.90-1.60%, maintaining excellent weldability.

Both ABS FH36 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: FH36 offers a minimum yield strength of 355 MPa with tensile strength of 490-620 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 510-650 MPa, designed for more demanding load-bearing applications requiring superior strength . Both grades feature strictly controlled chemical composition (carbon ≤0.16%, manganese 0.90-1.60%) 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