Difference between DNV D500 and DNV D690 steel plate

DNV D500 and DNV D690 are ultra-high-strength structural steel plates certified by Det Norske Veritas (DNV) for critical applications in shipbuilding and offshore engineering, such as heavy-load carrier hulls, high-pressure nodes, and specialized marine equipment. The "D" prefix indicates that the material's impact toughness is tested and guaranteed at a moderate low temperature of -20°C. The numerical suffix denotes the minimum yield strength in megapascals (MPa). Thus, DNV D500 provides a yield strength of at least 500 MPa, while DNV D690 offers a significantly higher minimum yield strength of 690 MPa.

Key Differences

The primary distinction lies in their strength grade and the resulting trade-offs in application scope, fabricability, and cost. DNV D690 provides approximately 38% higher yield strength than D500, enabling far greater load capacity or substantial structural weight savings. This makes D690 suitable for the most demanding structural components where maximum strength-to-weight ratio is paramount. However, achieving this ultra-high strength in D690 requires advanced metallurgical processes (such as quenching and tempering) and leads to significantly more stringent requirements for welding, cutting, and forming compared to D500. Consequently, DNV D500 offers a more favorable balance of high strength and practical fabricability for standard heavy-duty applications requiring reliable performance down to -20°C. The selection is therefore driven by project-specific demands: Choose DNV D690 where its extreme strength justifies the higher material cost and fabrication complexity for weight-critical or exceptionally high-load designs. Opt for DNV D500 for robust, high-strength applications where ease of fabrication and proven performance under moderate low-temperature conditions are prioritized.

Chemical Composition

Mechanical Property