Difference between DNV D and DNV E steel plate

DNV D and DNV E are standardized grades of shipbuilding and offshore structural steel plates certified by Det Norske Veritas (DNV), differentiated primarily by their low-temperature impact toughness requirements. When paired with a strength suffix (e.g., D420, E550), they form complete steel grades. In isolation, "DNV D" and "DNV E" typically refer to the standard strength grades of 235 MPa yield, equivalent to the base DNV A and B grades but with enhanced toughness.

Key Differences

The fundamental distinction is the minimum test temperature for impact toughness. DNV D grade steel is required to maintain adequate impact energy (resistance to brittle fracture) at a temperature of -20°C. DNV E grade steel must meet this requirement at the significantly lower temperature of -40°C. This designates the E grade as suitable for Arctic service, ice-going vessels, and structures operating in polar regions, where the risk of brittle fracture is highest. To achieve this superior low-temperature performance, the E grade undergoes stricter chemical composition control and processing (e.g., grain refinement) compared to the D grade. Therefore, DNV D is standard for general oceangoing vessels in cold climates, while DNV E is essential for operations in severe Arctic or Antarctic conditions.

Chemical Composition

Mechanical Property