Difference between DNV D420 and DNV D460 steel plate

DNV D420 is an extra-high-strength structural steel plate certified by DNV (Det Norske Veritas) for marine and offshore applications . The "D" designation signifies that the material's impact toughness is tested and guaranteed at -20°C . It has a minimum yield strength of 420 MPa (61 ksi) and tensile strength ranging from 530 to 680 MPa (77-99 ksi), with minimum elongation of 18% (transverse) . Impact energy requirements are minimum 42J (longitudinal) or 28J (transverse) at -20°C . The chemical composition is strictly controlled with carbon ≤0.20% and manganese ≤1.70% . This grade can be delivered in as-rolled, normalized, or quenched and tempered conditions . It is widely used for shipbuilding hulls, offshore platforms, and marine structures requiring reliable strength in moderate cold environments.

DNV D460 is an extra-high-strength structural steel plate also certified by DNV with impact toughness tested at -20°C . The "460" denotes a minimum yield strength of 460 MPa (67 ksi) . It has a tensile strength ranging from 570 to 720 MPa (83-105 ksi) and minimum elongation of 17% (transverse) . Impact energy requirements are minimum 46J (longitudinal) or 31J (transverse) at -20°C . The chemical composition features carbon ≤0.20%, manganese ≤1.70%, with microalloying elements . This grade is typically supplied in thermomechanical controlled processed (TMCP) or normalized conditions . It is designed for demanding structural components in shipbuilding, mobile offshore drilling units, and marine structures requiring superior strength.

Both DNV D420 and DNV D460 are DNV-certified extra-high-strength marine steels with impact toughness tested at -20°C, ensuring reliable performance in cold marine environments . Their primary difference lies in strength level: D420 offers a minimum yield strength of 420 MPa with tensile strength of 530-680 MPa, suitable for general high-strength hull construction and offshore platforms , while D460 provides a higher minimum yield strength of 460 MPa with tensile strength reaching 570-720 MPa, designed for more demanding load-bearing applications requiring superior strength. Both grades feature controlled chemical composition with carbon ≤0.20% and manganese ≤1.70% , and require controlled processing to achieve their mechanical properties while maintaining good weldability for critical marine service.

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Mechanical Property