LR AH32 Steel Plate | AH32 Shipbuilding Steel Plate

LR AH32 steel plate, also written as LR/AH32, LR Grade AH32, Lloyd's Register AH32 or simply AH32 ship steel plate, is the higher-strength hull structural steel of Lloyd's Register Rules for Ships (IACS UR W11 higher-strength family) with 315 MPa minimum yield, 440-590 MPa tensile strength and Charpy V-notch toughness at 0°C [32°F]. In the grade name, "A" is the toughness class, "H" means higher strength and "32" refers to the strength level (historically about 32 kgf/mm²). Gangsteel, a steel plate exporter, supplies LR AH32 plates cut to size for shipbuilding, offshore platforms and marine structures.

Data source: Per IACS UR W11 (ordinary/higher-strength hull structural steel) as adopted in Lloyd's Register Rules for Ships. Verify the current LR edition before ordering.

LR/AH32 Chemical Composition (Heat Analysis)

 

Element	C	Mn	Si	P	S	Al (acid sol.)
AH32, %	0.18 max	0.90-1.60	0.10-0.50	0.035 max	0.035 max	0.015 min
Element	Nb	V	Ti	Cu	Cr	Ni / Mo
AH32, %	0.02-0.05	0.05-0.10	0.02 max	0.35 max	0.20 max	0.40 max / 0.08 max

Per IACS UR W11 / LR Rules for Ships (higher-strength hull structural steel). Nb, V and Al grain-refining elements may be used singly or in combination; when used in combination the individual minima do not apply. Where acid-soluble Al is not less than 0.015%, the Si minimum does not apply. Carbon equivalent: Ceq = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15 (%). 依据 IACS UR W11 / LR Rules for Ships.

Product Analysis (Check Analysis)

 

IACS UR W11 / LR Rules for Ships do not separately tabulate product (check) analysis limits for higher-strength grades. When product analysis is required, the finished plate shall meet the heat limits subject to ASTM A6/A6M Table A permitted variations (same practice as ABS MW Pt2).

Element	Heat analysis limit	Product analysis (heat ± A6)
C	0.18 max	0.22 max
Mn	0.90-1.60	0.81–1.72
Si	0.10-0.50	0.04–0.56
P	0.035 max	0.045 max
S	0.035 max	0.045 max
Al (acid sol.)	0.015 min	no A6 Table A tolerance; product value not tabulated
Nb	0.02-0.05	0.010–0.060
V	0.05-0.10	0.040–0.110
Ti	0.02 max	0.03 max
Cu	0.35 max	0.38 max
Cr	0.20 max	0.24 max
Ni	0.40 max	0.43 max
Mo	0.08 max	0.09 max

依据 IACS UR W11 / LR Rules for Ships. Product analysis applies only when specified; for a range, results may not vary both above and below it.

LR/AH32 Mechanical Properties

 

Grade	Yield strength, min	Tensile strength	Elongation, min
LR/AH32	315 MPa [46 ksi]	440-590 MPa [64-85 ksi]	22%

Per IACS UR W11 / LR Rules for Ships. Yield and tensile values apply for the full thickness range covered by the grade (typically up to 100 mm for these ship plates).

Charpy V-Notch Impact Requirements (0°C [32°F])

 

Thickness	Test temperature	Longitudinal, avg min	Transverse, avg min
t≤50 mm	0°C [32°F]	31 J	22 J
50<t≤70 mm	0°C [32°F]	38 J	26 J
70<t≤100 mm	0°C [32°F]	46 J	31 J

Per IACS UR W11 / LR Rules for Ships. Average of three full-size Charpy V-notch specimens; not more than one value below the average and none below 70% of it. Longitudinal values shown; transverse values apply when required by the rules or purchase order.

Delivery Condition and Deoxidation

Deoxidation: Killed, fine-grain practice. Delivery condition: AH grades may be as-rolled, controlled rolled, normalized or TMCP depending on thickness; thicker plates usually N or TMCP. Optional extras by agreement include ultrasonic testing, Z-direction (Z15/Z25/Z35) through-thickness testing and third-party LR survey.

Thickness Coverage

Higher-strength LR AH/DH/EH/FH 32/36/40 plates are commonly supplied from about 6 mm to 100 mm thick (up to 150 mm by agreement). Width 1500-4000 mm and length 6000-18000 mm are typical.

Equivalent Steel Grades of LR/AH32

 

Society / Standard	Equivalent grade
LR (Lloyd's Register)	LR/AH32
ABS	ABS AH32 steel plate (AB/AH32)
CCS	CCS AH32 steel plate
ASTM A131/A131M	ASTM A131 AH32 steel plate
DNV	NV A32
GL	GL-A32
BV	BV/AH32
NK / KR / RINA	K A32 / R A32 / RI/A32

IACS member societies harmonize ordinary and higher-strength hull grades under UR W11; dual certification (for example LR + ABS, or LR + ASTM A131) is common when ordered that way.

FAQ about LR AH32 Steel Plate

What is LR AH32 steel plate?

It is a higher-strength hull structural steel under Lloyd's Register Rules for Ships (IACS UR W11), with 315 MPa minimum yield, 440-590 MPa tensile strength and Charpy toughness at 0°C [32°F].

What does AH32 stand for?

The letter A is the toughness class (Charpy at 0°C), H means higher strength, and 32 is the strength level (historically about 32 kgf/mm², now 315 MPa min yield).

What is the yield strength of LR AH32?

Minimum 315 MPa (46 ksi), tensile 440-590 MPa (64-85 ksi), elongation about 22% min.

What is the impact test temperature for LR AH32?

Charpy V-notch at 0°C [32°F]. Longitudinal average minima are 31 J up to 50 mm, 38 J for 50-70 mm and 46 J for 70-100 mm.

What is the difference between LR AH32 and LR DH32?

AH32 is impact tested at 0°C; DH32 at -20°C. Same strength class.

Is LR AH32 the same as ABS AH32 or ASTM A131 AH32?

Requirements are essentially harmonized under IACS UR W11. ABS AH32 and ASTM A131 AH32 are counterparts; dual certification is common when ordered with the required surveys.

Is LR AH32 weldable?

Yes. Controlled carbon and Ceq give good weldability; preheat may be required for thick sections depending on Ceq and restraint.

What heat treatment is required for LR AH32?

AH32 may be AR/CR/N/TMCP by thickness; thicker plates are usually normalized or TMCP.

What thickness is available for LR AH32?

Typical supply is about 6-100 mm thick (up to 150 mm by agreement), 1500-4000 mm wide and 6000-18000 mm long.

Other LR Steel Plate Grades

LR Grade A steel plate | LR Grade B steel plate | LR Grade D steel plate | LR Grade E steel plate | LR AH36 steel plate | LR AH40 steel plate | LR DH32 steel plate | LR DH36 steel plate | LR DH40 steel plate | LR EH32 steel plate | LR EH36 steel plate | LR EH40 steel plate | LR FH32 steel plate | LR FH36 steel plate | LR FH40 steel plate

Equivalent Class Society Grades

LR AH32 corresponds to the same grade under the other IACS member classification societies and ASTM A131: CCS AH32 steel plate, ABS AH32 steel plate, ASTM A131 AH32 steel plate, GL AH32 steel plate, DNV A32 steel plate, BV AH32 steel plate, NK A32 steel plate, KR A32 steel plate, RINA AH32 steel plate.