Shipbuilding Steel Plate

Shipbuilding steel plate is a specialized hot-rolled steel plate manufactured according to the specifications of classification societies (such as CCS, DNV, ABS, etc.) for use in ship hull structures. It possesses high strength, high toughness, good weldability, and resistance to seawater corrosion.

Shipbuilding Steel Plates are hot-rolled steel materials specifically used for constructing ship hulls and critical structures. Their main applications include load-bearing components such as hull plating, decks, bulkheads, keels, and ribs. They are also used in special areas such as liquid cargo tanks (e.g., 9Ni steel for LNG carriers, corrosion-resistant steel for crude oil tankers), deck machinery, ballast tanks, and cargo hold bulkheads.

Categories: STEEL PLATE, Shipbuilding Steel Plate

Description

Description

Shipbuilding steel plate, also known as Marine Steel Plate, is a specialized hot-rolled steel plate manufactured according to the specifications of classification societies (such as CCS, DNV, ABS, etc.) for use in ship hull structures. It possesses high strength, high toughness, good weldability, and resistance to seawater corrosion.

Standards and Requirements for Shipbuilding Steel Plates:

International standards for shipbuilding steel plates are primarily harmonized by the International Association of Classification Societies (IACS) and implemented by national classification societies (such as ABS, DNV, LR, CCS, etc.). Core specifications include IACS UR W11 and the respective societies’ classification rules for steel seagoing vessels.

Commonly used international standards for shipbuilding steel plates include ISO 16188 and some ASTM/AISI series standards, but in practice, classification society certification takes precedence.

IACS Unified Requirements UR W11: This specification generally addresses the mechanical properties, chemical composition, delivery condition, and certification procedures for high-strength shipbuilding structural steels (such as A, B, D, E, AH32/DH32/EH32, AH36, etc.), and serves as the foundation for global classification societies.

ISO 16188:2018: “Marine and marine technology — Structural steel for marine use — Classification, technical conditions,” covers general strength (235 MPa) and high strength (315–420 MPa) steels, equivalent to the designation systems of most classification societies.

The Shipbuilding Steel Plate classification society standards are dominant: such as the US ABS “Guidelines for the Certification of Steel for Shipbuilding,” Norway’s DNV-GL RP-C201, the UK LR “Materials and Welding,” and China’s CCS “Classification Rules for Steel Seagoing Ships,” etc. Although they have national attributes, due to IACS harmonization and mutual recognition, obtaining certification from any major classification society (such as ABS, DNV, LR, CCS, BV, KR, NK) is the practical way to implement “international standards” in international trade and construction.

Common standards for shipbuilding steel plates include ASTM A131/A131M (American standard, widely cited) and EN 10225 (European standard, used for non-IACS projects), which are regional references and do not replace classification society certification.

The corresponding Chinese national standard is GB/T 712-2022 (equivalent to IACS UR W11 requirements), but export or international projects still require an additional classification society certificate.

Shipbuilding steel plates must simultaneously meet requirements for chemical composition (e.g., C≤0.18–0.22, Mn≥0.9–1.6, P/S≤0.035), mechanical properties (yield strength 235–420 MPa), impact toughness at -20°C to -60°C, and weldability, and must be approved by the classification society factory and certified batch by batch (marked as “ABS A” or “DNV EH36”).

Shipbuilding steel plates do not have a single “international standard number”; the validity of certification depends on the selected classification society and its IACS recognition status.

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