Advantages of DNV EH36 Marine Steel Plates for Use in Polar Icebreakers and Heavy-Load Deep-Sea Offshore Engineering Projects

1. Impact toughness at -40°C, suitable for extreme polar environments

The core advantages of DNV EH36 lie in its stable low-temperature impact performance and refined internal microstructure. Compared to AH36 (0°C impact test) and DH36 (-20°C impact test), EH36 is required to undergo certification via a -40°C Charpy V-notch impact test.

Its uniform ferritic-pearlitic microstructure helps suppress brittle fracture under the combined effects of ultra-low temperatures and ice loads, effectively mitigating the risk of failure that conventional Grade 36 steel may face during polar navigation and in deep-sea low-temperature environments.

2. High-Strength Properties Support Heavy-Load Structural Design

DNV EH36 has a minimum yield strength of 355 MPa and a tensile strength of 490–630 MPa, with a structural load-bearing capacity approximately 12% higher than that of EH32 steel.

These enhanced strength properties allow engineers to implement lightweight, high-rigidity integrated designs for hulls and platform structures, helping to reduce the deadweight of large polar vessels, increase speed and cargo capacity, and lower fuel consumption and operating costs during trans-polar voyages.

3. Excellent Marine Corrosion Resistance and Fatigue Performance

DNV EH36 employs an optimized, low-impurity copper-nickel microalloyed composition system that forms a dense, stable protective oxide film on the steel surface in high-salinity, low-temperature marine environments, effectively resisting seawater immersion, atmospheric spray, and freeze-thaw cycling corrosion.

At the same time, the normalizing heat treatment refines the grain structure, enhancing the steel’s fatigue resistance to long-term wave impact and alternating loads. Compared to conventional DH36 steel, its design service life in heavy-duty structures in cold seas can be extended by more than 40%.

4. Stable Welding Performance and Strong Adaptability to Low-Temperature Construction

DNV EH36 strictly controls the maximum carbon equivalent (CEV) to ≤ 0.40%, resulting in low susceptibility to hydrogen-induced cracking during welding and good process adaptability. It supports mainstream marine welding processes such as submerged arc welding, gas shielded arc welding, and manual arc welding.

Even under ultra-low-temperature polar construction conditions, defects such as welding cracks, lack of fusion, and reduced toughness in the heat-affected zone can be effectively prevented through standardized preheating and interpass temperature control. Additionally, it exhibits excellent cutting, bending, and cold forming properties, making it suitable for the complex curved surface processing and thick-plate joining requirements of polar vessels.

5. International Authoritative Certifications and Qualifications for High-End Projects

As a DNV-certified cryogenic high-strength marine steel, EH36 meets the unified requirements of international classification societies and is widely recognized by major global ship inspection agencies.

It fully complies with material selection standards for polar icebreaking projects, deep-sea floating platforms, and high-end offshore facilities in cold seas, providing a reliable basis for bidding, acceptance, and qualification reviews in international projects with high standards.