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DNV Grade AH36 Shipbuilding Steel Plate - NV A36 High-Strength Marine Steel

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DNV Grade AH36 shipbuilding steel plate is a high-strength structural steel plate certified by DNV that offers excellent yield strength, superior weldability, and outstanding low-temperature impact resistance. It is widely used in shipbuilding and offshore engineering. All of our DNV Grade AH36 shipbuilding steel plates have undergone comprehensive certification by DNV and comply with the latest DNV ship classification rules. Each batch is accompanied by an official Mill Test Certificate (MTC), supporting third-party inspection and full traceability.

Certification :
DNV Rules
Grade :
DNV Grade AH36 (NV A36)
Thickness :
5.0 - 150.0 mm
Width :
1500.0 - 4000.0 mm
Length :
6000.0 - 18000.0 mm

Special thickness, width, and length can be negotiated separately.
We also provide customized processing services.If you have any questions, please contact us.

Overview

1. What is DNV Grade AH32 shipbuilding steel plate?

DNV Grade AH36 (NV A36) is a high-strength, low-alloy marine structural steel plate certified by DNV (Det Norske Veritas). This steel plate offers excellent yield strength (≥ 355 MPa), tensile strength (490–630 MPa), low-temperature toughness (0°C), weldability, and corrosion resistance. It is capable of withstanding harsh environments such as marine salt spray corrosion and wave impact, making it a critical structural material in modern shipbuilding and offshore engineering.

2. Meaning of the Designation

DNV: Certified by Det Norske Veritas (DNV)

A: Quality grade A (Impact testing must be conducted at 0°C)

H: High-strength steel

36: Minimum yield strength: 355 MPa (≈ 36 kgf/mm²)

Available Specifications and Dimensions

Product	DNV Grade AH36 Shipbuilding Steel Plate
Certification	DNV
Grade	NV A36
Classification	High-Strength Structural Steel for Ship and Ocean Engineering
Thickness	5 - 150 mm
Width	1500 - 4000 mm
Length	6000 - 18000 mm
Delivery Conditions	Hot Rolled (HR), Controlled Rolled (CR), Normalized (N), Thermo-Mechanical Controlled Processed (TMCP), Quenched and Tempered (Q+T).
Surface Conditions	The surface is in its original condition; surface treatments such as sandblasting, rust removal, oiling and painting are available.
Testing	Tensile test, Charpy V-notch impact test, Ultrasonic testing (UT), Z-direction property test (Grades Z15/Z25/Z35).
Applications	It is primarily used to manufacture load-bearing structures for various types of vessels in temperate waters and components for offshore marine engineering platforms.
MOQ	5 tons (small orders can be negotiated).
Delivery Time	15 - 20 days after order confirmation (urgent orders accepted)
Packaging	Standard export packaging for sea transport, or as required.
Country of origin	China
Quality	Provide complete Mill Test Certificates (MTC) and DNV certification, and support third-party testing by SGS, BV, and others.

Chemical Composition

Chemical Composition (Heat Analysis, wt %)

Grade	C	Si	Mn	P	S	Cu	Cr	Ni	Nb	V	Ti	Mo	Als
NV A36	≤ 0.18	≤ 0.50	0.90 - 1.60	≤ 0.030	≤ 0.030	≤ 0.35	≤ 0.20	≤ 0.40	0.02 - 0.05	0.05 - 0.10	≤ 0.02	≤ 0.08	≥ 0.015

Carbon Equivalent (wt %)

Thickness (mm)	5 - 50	50 - 150
Typical CEV (wt %)	≤ 0.38	≤ 0.40

Calculation formula (IIW): CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15

Mechanical Properties

Tensile Test

Grade	Yield Strength (ReH), MPa	Tensile Strength (Rm), MPa	Elongation (A), %
NV A36	≥ 355	490 - 630	≥ 21

Charpy (V-notch) Impact Test

Grade	Thickness, mm	Temperature, ℃	Impact Energy, KV₂ / J
Grade	Thickness, mm	Temperature, ℃	Longitudinal	Transverse
NV A36	≤ 50	0	≥ 34	≥ 24
	> 50 - 70	0	≥ 41	≥ 27
	> 70 - 150	0	≥ 50	≥ 34

Applications

1. Shipbuilding

1.1 High-Strength Load-Bearing Structures of the Main Hull

Applicable to ocean-going cargo ships, bulk carriers, container ships, oil tankers, general cargo ships, roll-on/roll-off (RO-RO) ships, and offshore support vessels of 10,000 DWT and above:

· High-strength decks and deck side plates

· Top plates of the sides, middle and upper sections of the outer side plating

· Main longitudinal frames, stiffening beams, rib frames, and longitudinal frames of the sides

· Longitudinal bulkheads, ballast tank bulkheads

1.2 Superstructure and Auxiliary Structures

· Freeboard deck, fore/aft deck outer walls, engine room bulkheads, platform deck

· Mast bases, davit bases, mooring chock bases, crane base plates, marine crane support structures

· Cargo hatch coamings, hatch cover load-bearing panels, pipe supports, seawater valve box housings

2. Offshore Engineering

2.1 Upper modules of fixed offshore oil and gas platforms

Platform decks, walkways, support trusses, equipment bases (applicable to temperate waters)

2.2 FPSO/FPU floating production, storage, and offloading units

Decks, side walls, and support frames in non-subzero regions

2.3 Offshore Wind Power Substation Platforms and Jack-up Platforms: Secondary Load-bearing Plates

2.4 Other Offshore Structures

Subsea pipeline supports, offshore module assembly structures, jetties

3. Port Machinery and Coastal Heavy Industry

· Main beams, outriggers, and platform plates for port gantry cranes, ship loaders, and unloaders

· Cross-sea causeways, quay fender bases, and floating dock structures

· Seawater intake and discharge tanks for coastal power plants, and coastal steel structures

4. Ship Repair and Refitting

· Hull repair

· Structural reinforcement

· Component replacement

Other Information

Key Features and Advantages

1. Authoritative DNV Classification Certification

Every batch of DNV AH36 shipbuilding steel plates is certified by DNV and supports third-party inspection.

2. High Structural Strength

Effectively reduces steel consumption and hull weight, thereby enhancing load-carrying capacity and operational efficiency.

3. Excellent Marine Corrosion Resistance

Demonstrates outstanding resistance to seawater corrosion, salt spray erosion, and atmospheric aging, significantly extending the service life of hulls and offshore structural components.

4. Excellent Welding and Formability

With stable chemical composition and low carbon equivalent, the steel is resistant to cracking during welding and cold bending, facilitating on-site construction and assembly.

5. High Dimensional Accuracy and Surface Quality

Strict rolling tolerance controls ensure a flat, smooth surface free of surface defects such as cracks, scars, and inclusions.

Our Supply Advantages

1. Comprehensive DNV Certification

All products are officially certified by DNV, with complete documentation to support global project acceptance and customs clearance.

2. Strict Quality Control

Every batch of steel plates undergoes testing for mechanical properties, chemical composition, and surface quality to ensure no substandard products are shipped.

3. Stable Supply Capacity

We maintain ample inventory, and our prices are even more competitive for bulk orders.

4. Custom Processing Services

We offer value-added services such as custom sizing, precision cutting, surface treatment, and heat treatment.

5. Global Delivery

With extensive export experience, we support trade terms such as FOB, CIF, and CFR, ensuring timely delivery to all ports worldwide.

FAQ

Q1:

What is the weldability of DNV Grade AH36 steel?

DNV Grade AH36 steel has excellent weldability; however, preheating conditions and process parameters must be strictly controlled during actual welding. The specific points are as follows:

1. Preheating Requirements

For fillet and butt welds with plate thicknesses > 30 mm, the preheating temperature before welding should be 120 - 150 °C;

For plate thickness ≤ 30 mm and ambient temperatures below 5 °C, the preheating temperature should not be lower than 75 °C.

2. Common Welding Methods

Conventional arc welding processes such as Shielded Metal Arc Welding (SMAW), Submerged Arc Welding (SAW), and Flux-Cored Arc Welding (FCAW) are recommended.

3. Welding Quality

Relevant studies indicate that, under appropriate welding procedure specifications (WPS), the impact toughness of all regions (weld, fusion zone, and heat-affected zone) in DNV Grade AH36 welded joints meets the requirements of classification society regulations, demonstrating good process adaptability.

Q2:

What are the differences between NV A36, NV D36, and NV E36 shipbuilding steel plates?

The key differences between these three types of shipbuilding steel plates lie in their low-temperature impact toughness and applications:

Grade	Yield Strength	Tensile Strength	Impact Test Temperature	Applications
NV A36	≥ 355 MPa	490–630 MPa	0°C	Coastal vessels, decks, superstructures, mild-temperature waters
NV D36	≥ 355 MPa	490–630 MPa	-20°C	Vessels in cold regions, hull bottoms, bulkheads
NV E36	≥ 355 MPa	490–630 MPa	-40°C	Arctic vessels, offshore platforms, low-temperature marine structures

Note: Do not substitute grades arbitrarily; adhere to DNV design temperature requirements.

Q3:

Do you offer custom processing for marine steel plates?

Yes, we provide a range of value-added services, including cutting, bending, drilling, rust removal, and painting, and can customize dimensions and processing solutions based on customer drawings and project requirements.

Q4:

Do you provide certified MTC documents for DNV Grade AH36 shipbuilding stee plates?

Yes. We provide MTC compliant with DNV standards for each batch of products, which support third-party inspection.

Q5:

What is the difference between DNV Grade AH36 and DNV Grade DH36 shipbuilding steel plates?

Both are high-strength structural steel plates for shipbuilding with a yield strength of at least 355 MPa, in compliance with DNV regulations. The key difference lies in the minimum service temperature:

AH36: Design operating temperature ≥ 0°C, impact test temperature 0°C; suitable for warm waters.

DH36: Offers superior low-temperature toughness, with an impact test temperature of -20°C, and is suitable for cold waters.