Description

AH36 Shipbuilding Steel Plate is a high-strength structural shipbuilding steel plate certified by international classification societies (such as CCS, ABS, DNV, etc.), also as known as AH36 Marine Steel Plate. In the grade designation, “A” represents the quality grade (Class A), “H” represents high strength, and “36” indicates a yield strength of not less than 355 MPa (approximately 51 ksi).

Features of AH36 Shipbuilding Steel Plate:

1. High Strength: AH36 Shipbuilding Steel Plate has a yield strength ≥355 MPa and a tensile strength of 490–620 MPa, allowing for thinner plates and reduced hull weight while maintaining structural strength.

2. Good Low-Temperature Toughness: Standard requirements include a Charpy V-notch impact energy ≥34 J (longitudinal) at -20℃. Some certifications (such as DNV) support applications at -40℃ (must be clearly marked as AH36–40 or similar).

3. Excellent weldability: Low carbon equivalent (Ceq ≤0.40%) and microalloying (Nb, V, Ti micro-addition) design supports high heat input welding of 20–50 kJ/cm, typically requiring only ≤75℃ preheating (under normal conditions).

4. Controlled rolling and cooling (TMCP) process: Most are delivered in TMCP or controlled rolling condition, ensuring uniform properties throughout the thickness direction and grain refinement to ASTM grade 10 and above.

5. Corrosion resistance: The AH36 Shipbuilding Steel Plate substrate contains trace amounts of Cu (0.02–0.05%) to promote a dense rust layer, but marine environmental protection is mainly achieved through coatings (such as epoxy zinc-rich coatings); it is not a “corrosion-resistant steel” and requires a corresponding anti-corrosion system.

6. Standards: Complies with GB/T 712-2011 (China), ABS/AH36, DNV GL, LR, and other international classification society standards. Basic mechanical properties remain unchanged regardless of the classification society, but certification details (such as impact test temperature and Z-axis performance) may differ.

7. Thickness Range: Standard 8–150 mm. Extra-thick plates (>60 mm) require special processes to ensure core performance. Delivery conditions are mostly hot-rolled, controlled-rolled, or TMCP.

Note: AH36 Shipbuilding Steel Plate is a Class A high-strength steel. The difference between it and Classes B/D/E lies in their low-temperature impact requirements (Class A only -20℃, while Classes D/E can reach -40℃ or lower). For higher toughness or Z-axis performance (resistance to lamellar tearing), derivative grades such as AH36D and AH36-Z35 should be selected.

Applications of AH36 Shipbuilding Steel Plate:

AH36 Shipbuilding Steel Plate is a high-strength (yield strength ≥355MPa), Grade A (0℃ impact toughness requirement) steel for ship hulls and marine engineering structures. It is primarily used in the construction of critical load-bearing structures for ships and offshore platforms under moderate loads and normal sea conditions.

1. Shipbuilding: AH36 Shipbuilding Steel Plate is used for the main hull structure of bulk carriers, tankers, container ships, and engineering vessels, including decks, side plating, bulkheads, bottom plating, and keels, balancing strength and weldability.

2. Marine Engineering: AH36 Shipbuilding Steel Plate is suitable for load-bearing components in non-extremely cold regions, such as jackets, pile legs, and deck supports for drilling platforms, production platforms, and wind power installation platforms.

3. Ports and Special Equipment: AH36 Shipbuilding Steel Plate is used for quay cranes, ship loaders, large lifting equipment, LNG carrier shielding layers, and auxiliary structures for chemical tankers, but it is not suitable for long-term polar environments below -20°C (in which case DH36/EH36 should be selected).

4. Offshore Facilities: AH36 Shipbuilding Steel Plate is used for temporary or auxiliary steel structures such as bridge piers, derricks, and offshore piers, but it is not a mainstream design material.

Standards of Shipbuilding Steel Plate:

ASTM A131 Steel Plate Chemical Composition (max.)
Grade	C	Mn	Si	P	S	Others
Grade A	0.21	2.5xC	0.5	0.035	0.035
Grade B	0.21	0.6	0.35	0.035	0.035
Grade D	0.21	0.6	0.01-0.35	0.035	0.035
Grade E	0.18	0.7	0.01-0.35	0.035	0.035
AH32/DH32/EH32	0.18	0.90-1.60	0.10-0.50	0.035	0.035	Cb 0.02-0.05, V 0.05-0.10, Ti 0.02, Cu 0.35, Cr 0.20, Ni 0.40, Mo 0.08, Als min. 0.015
AH36/DH36/EH36
AH40/DH40/EH40
FH32/FH36/FH40	0.16	0.90-1.60	0.10-0.50	0.025	0.025

ASTM A131 Steel Plate Mechanical Properties
Grade	Yield Strength	Tensile Strength	Elongation in 8 in.	Elongation in 2 in.
Grade	min. MPa)	MPa	min. %	min. %
Grade A, B, D, and E	235	400-520	21	24
AH32 DH32 EH32 FH32	315	440-590	19	22
AH36 DH36 EH36 FH36	355	490-620	19	22
AH40 DH40 EH40 FH40	390	510-650	19	22

ASTM A131 Steel Plate Charpy V-Notch Impact Test Temperature
Grade	Temperature ⁰F [⁰C]
Grade A	68 [20]
Grade B AH32 AH36 AH40	32 [0]
Grade D DH32 DH36 DH40	-4 [-20]
Grade E EH32 EH36 EH40	-40 [-40]
FH32 FH36 FH40	-76 [-60]

Standard	Shipbuilding and Offshore Structure Steel Grades
ASTM A131	Grade A	Grade B	Grade D	Grade E
	AH32	DH32	EH32	FH32
	AH36	DH36	EH36	FH36
	AH40	DH40	EH40	FH40
EN 10225	S355G2+N	S355G3+N	S355G5+M	S355G6+M
	S355G7+M	S355G7+N	S355G8+M	S355G8+N
	S355G9+N	S355G9+M	S355G10+N	S355G10+M
	S420G1+Q	S420G1+M	S420G2+Q	S420G2+M
	S460G1+Q	S460G1+M	S460G2+Q	S460G2+M
API SPEC 2H	API 2H-42	API 2H-50

Steel Grade	C	Si	Mn	P	S	Als
A	≤0.21	≤0.50	≥2.5c	≤0.035	≤0.035
B	≤0.21	≤0.35	0.8~1.2	≤0.035	≤0.035
D	≤0.21	≤0.35	0.6~1.2	≤0.035	≤0.035	≥0.015
E	≤0.18	≤0.35	0.7~1.2	≤0.035	≤0.035	≥0.015
AH32	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
DH32	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
EH32	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
FH32	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
AH36	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
DH36	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
EH36	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
FH36	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
AH40	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
DH40	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
EH40	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015
FH40	≤0.18	≤0.50	0.9~1.6	≤0.035	≤0.035	≥0.015

Standards and Classifications

Standard	Shipbuilding and Offshore Structure Steel Plate Grades
ASTM A131	Grade A	Grade B	Grade D	Grade E
	AH32	DH32	EH32	FH32
	AH36	DH36	EH36	FH36
	AH40	DH40	EH40	FH40
EN 10225	S355G2+N	S355G3+N	S355G5+M	S355G6+M
	S355G7+M	S355G7+N	S355G8+M	S355G8+N
	S355G9+N	S355G9+M	S355G10+N	S355G10+M
	S420G1+Q	S420G1+M	S420G2+Q	S420G2+M
	S460G1+Q	S460G1+M	S460G2+Q	S460G2+M
API SPEC 2H	API 2H-42	API 2H-50