In the demanding world of marine engineering and shipbuilding, structural integrity, safety, and performance are non-negotiable. Ships and offshore structures operate in some of the harshest environments on Earth — exposed to saltwater corrosion, extreme pressure, high impact loads, and temperature variations. Selecting the right steel for these conditions determines not only the longevity of a vessel but also its efficiency and safety at sea.
Among the most widely recognized and trusted materials in the industry are AH36, DH36, and EH36 shipbuilding steel plates. These grades belong to the family of high-strength low-alloy steels specifically developed for ship hulls, offshore platforms, and marine equipment that demand superior strength and resilience.
As a certified global supplier of marine-grade steel, sakysteel provides AH36, DH36, and EH36 plates that meet the stringent standards set by classification societies such as ABS, DNV, LR, BV, and CCS, ensuring consistent performance and reliability for critical marine applications.
AH36, DH36, and EH36 are all part of the ASTM A131 and ABS steel standards, designed for high-strength structural applications in shipbuilding. While they share similar mechanical and chemical characteristics, their impact toughness differentiates them.
| Steel Grade | Yield Strength (MPa) | Tensile Strength (MPa) | Impact Test Temperature | Application |
|---|---|---|---|---|
| AH36 | 355 | 490–620 | 0°C | General ship hulls and decks |
| DH36 | 355 | 490–620 | -20°C | Offshore structures and cold seawater exposure |
| EH36 | 355 | 490–620 | -40°C | Arctic conditions, deep-sea and polar vessels |
Each grade provides a yield strength of 355 MPa and a tensile strength up to 620 MPa, ensuring excellent resistance to deformation and failure under heavy loading.
The alloy composition of AH36, DH36, and EH36 is carefully engineered to balance strength, weldability, and corrosion resistance.
Typical Chemical Composition (%):
Carbon (C): ≤ 0.18
Manganese (Mn): 0.90–1.60
Silicon (Si): 0.10–0.50
Phosphorus (P): ≤ 0.035
Sulfur (S): ≤ 0.035
Niobium (Nb), Vanadium (V), Titanium (Ti): ≤ 0.10
The addition of micro-alloying elements like niobium and vanadium refines grain size, enhancing both toughness and strength. This controlled chemistry ensures the steels perform reliably even under the most severe maritime conditions.
All three grades are engineered to achieve the optimal combination of high yield strength, tensile strength, and ductility.
Yield Strength: ≥ 355 MPa
Tensile Strength: 490–620 MPa
Elongation (in 50 mm): ≥ 21%
Charpy Impact Energy:
AH36: Tested at 0°C
DH36: Tested at -20°C
EH36: Tested at -40°C
These properties make AH36, DH36, and EH36 the materials of choice for high-strength marine applications that must endure rough seas and extreme loads.
One of the primary advantages of these grades is their high strength combined with reduced weight. This allows shipbuilders to design lighter hulls without compromising safety. The result is improved fuel efficiency, greater payload capacity, and reduced emissions, aligning with modern maritime sustainability goals.
Ships operating in cold regions or polar waters require materials that retain toughness at sub-zero temperatures. DH36 and EH36, in particular, are tested for impact resistance at -20°C and -40°C, ensuring ductility and crack resistance even in icy environments.
Saltwater and humidity accelerate corrosion, which can compromise a ship’s structural integrity. The chemical composition of AH36, DH36, and EH36 provides superior resistance to rust and oxidation, extending the service life of vessels and reducing maintenance costs.
These steels exhibit excellent weldability without preheating, thanks to their low carbon equivalent value (CEV). They can be welded using SMAW, GMAW, or SAW techniques without compromising strength or structural performance. This makes them highly suitable for large-scale shipyard fabrication.
Marine vessels constantly face cyclic stresses from waves, cargo movement, and propulsion vibration. AH36, DH36, and EH36 steels possess superior fatigue strength, helping prevent micro-cracking and ensuring long-term durability in demanding service conditions.
All three grades are approved by major classification societies:
ABS (American Bureau of Shipping)
Lloyd’s Register (LR)
Det Norske Veritas (DNV)
Bureau Veritas (BV)
China Classification Society (CCS)
This ensures that steel plates supplied by sakysteel meet international safety and performance requirements for shipbuilding and offshore engineering.
AH36 and DH36 plates are widely used in hull structures, decks, and frames of cargo vessels, tankers, and container ships. Their strength helps withstand wave pressure and impact loads without deformation.
EH36 steel, with its superior toughness at low temperatures, is ideal for offshore drilling rigs, floating production storage and offloading (FPSO) units, and subsea platforms that operate in harsh marine environments.
EH36 steel plates maintain excellent ductility in cryogenic conditions, making them suitable for liquefied natural gas (LNG) carriers, icebreakers, and Arctic expedition vessels.
Due to their combination of strength, lightweight design, and impact resistance, these steels are extensively used in naval frigates, patrol ships, and defense vessels, ensuring superior combat readiness and maneuverability.
AH36, DH36, and EH36 are also used in offshore wind turbine foundations, mooring systems, and support frames, where they provide long-term resistance to fatigue and corrosion under dynamic ocean conditions.
Hot Rolling and TMCP (Thermo-Mechanical Controlled Processing):
These steels are manufactured through TMCP, producing fine-grained microstructures that improve both strength and weldability.
Formability:
The excellent ductility of AH36, DH36, and EH36 allows easy bending and forming without cracking or internal stress buildup.
Cutting and Machining:
Compatible with plasma, oxy-fuel, and laser cutting techniques, ensuring precision and minimal heat distortion.
Surface Treatment:
Plates can be supplied in shot-blasted, primed, or coated finishes to enhance corrosion resistance during transportation and storage.
sakysteel ensures that every AH36, DH36, and EH36 plate undergoes rigorous testing before delivery:
Chemical Composition Analysis (spectrometry)
Tensile Strength and Elongation Tests
Charpy V-Notch Impact Tests at specified temperatures
Ultrasonic Testing (UT) for internal flaws
Dimensional and Surface Inspection
All products are delivered with EN 10204 3.2 Mill Test Certificates, confirming compliance with international standards and classification requirements.
As a professional manufacturer and exporter of marine and offshore steels, sakysteel offers unmatched product quality and customer support:
Full range of thickness (5–150 mm) and width (up to 3,500 mm)
Certification from ABS, LR, DNV, BV, and CCS
Customized dimensions and cutting services
Fast delivery with seaworthy packaging
Global supply network for shipyards and offshore projects
With sakysteel, clients can rely on high-quality AH36, DH36, and EH36 steel plates that meet the most demanding operational and safety requirements of the global marine industry.
The future of shipbuilding and offshore engineering is being shaped by advancements in lightweight, energy-efficient, and sustainable materials. As vessels grow larger and more specialized, the demand for high-strength low-alloy steels like AH36, DH36, and EH36 continues to rise.
Emerging applications include:
Hybrid propulsion vessels requiring weight-optimized hull materials
Deep-sea mining and exploration platforms built for ultra-deep conditions
Green shipping technologies, where corrosion-resistant steels reduce maintenance and emissions
Continuous innovation in steel processing — such as thermo-mechanical rolling and microalloying — ensures that these grades will remain at the forefront of marine engineering for decades to come.
In modern shipbuilding and offshore engineering, the balance between strength, safety, and performance is critical. AH36, DH36, and EH36 steel plates have earned their reputation as the preferred materials for high-strength marine applications, offering exceptional toughness, corrosion resistance, and weldability across all environments.
From commercial cargo ships and oil tankers to polar research vessels and offshore platforms, these steels ensure reliability and durability where failure is not an option.
Supported by global certifications, precision manufacturing, and decades of metallurgical expertise, sakysteel continues to deliver AH36, DH36, and EH36 shipbuilding plates that set the standard for marine excellence. As the maritime world advances toward safer, cleaner, and more efficient operations, these high-strength steels remain the foundation for building the ships and offshore structures of the future.