ABS AH40 Steel Plate – Properties, Chemistry & Equivalents

ABS AH40 (also written AB/AH40, ABS Grade AH40, AH40 steel plate) is a higher-strength hull structural steel plate to ABS Rules Part 2, Chapter 1, Section 3. The figure 40 is the strength class (minimum yield 390 MPa, tensile 510-650 MPa) and the letter A sets the Charpy V-notch test temperature of 0°C. It is killed and fine-grain treated, with Nb, V, Ti or Al used as grain refiners, and corresponds to grade A40 in IACS UR W11 and AH40 in ASTM A131.

Related grades: ABS DH40 steel plate ABS EH40 steel plate ABS FH40 steel plate ABS AH32 steel plate.

Gangsteel is specialized in supplying ABS high strength steel plate in ABS Grade AH40. For more information of GradeAH40 steel plate, please check them in following:

 

 

 

AB/AH40 high Strength Chemical Composition

AB/AH40

ABS AH40 chemical composition, % – heat (ladle) analysis and product (check) analysis

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

Al, Nb and V minima apply when used singly (combined minima per ABS 2-1-3/5); Si min does not apply where acid-soluble Al ≥ 0.015%; AH ≤ 12.5 mm may have Mn min 0.70%. Product analysis = heat limit ± ASTM A6/A6M Table A permitted variation (band chosen by the specified maximum/upper limit); applies only when product (check) analysis is required; for a range, results may not vary both above and below it. Per ABS Rules for Materials and Welding Part 2 (2022); product analysis tolerances per ABS 2-1-2/5.3 (“chemical tolerances of ASTM A6”) and ASTM A6/A6M 7.2, Table A (also invoked by ASTM A131). Heat limits: ABS 2-1-3/7.3 Table 1 (t ≤ 150 mm).

Crack Sensitivity:  Pcm = (C+Si/30+Mn/20+Cu/20+Ni/60+Cr/20+Mo/15+V/10+5B)%
Carbon Equivalent:  Ceq = 【C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15】%

 

 

 

AB/AH40 high strength property

AB/AH40

ABS AH40 mechanical properties by thickness

Thickness (mm)	Yield min (MPa)	Tensile (MPa)	Elongation A5 min (%)	Charpy test temp (°C)	Impact avg min, longitudinal (J)	Impact avg min, transverse (J)
t≤50	390	510-650	20	0	39	26
50<t≤70	390	510-650	20	0	46	31
70<t≤100	390	510-650	20	0	55	37

Source: ABS Rules Pt 2, 2-1-3 Tables 2 & 4. Either direction acceptable.

Boiler steel plates| Alloy steel plates| High strength plate| Carbon steel plate

 

 

 

 

 

Equivalent steel grade of AB/AH40
DNV	GL	LR	BV	CCS	NK	KR	RINA
NV A40	GL-A40	LR/AH40	BV/AH40	CCS/A40	K A40	R A40	RI/A40

 

 

 

 

If you need more stock steel plates in shipbuilding steel plate, please click warehouse sizes.

 

 Related steel grades: AB/AH36, AB/AH32, AB/D, AB/A

 

ABS Steel Plate Grade Supplier
General Strength	AB/A	AB/B	AB/D	AB/E
High Strength	AB/AH32	AB/DH32	AB/EH32	AB/FH32
	AB/AH36	AB/DH36	AB/EH36	AB/FH36
	AB/AH40	AB/DH40	AB/EH40	AB/FH40
Extra Strength	AB/AQ43	AB/DQ43	AB/EQ43	AB/FQ43
	AB/AQ47	AB/DQ47	AB/EQ47	AB/FQ47
	AB/AQ51	AB/DQ51	AB/EQ51	AB/FQ51
	AB/AQ56	AB/DQ56	AB/EQ56	AB/FQ56
	AB/AQ63	AB/DQ63	AB/EQ63	AB/FQ63
	AB/AQ70	AB/DQ70	AB/EQ70	AB/FQ70

 

 

 

ABS AH40 thickness and impact requirements

ABS impact energy rises with plate thickness. ABS AH40 is tested at 0°C. Minimum average energies (full-size specimens):

• t≤50 mm: 39 J longitudinal / 26 J transverse
• 50<t≤70 mm: 46 J longitudinal / 31 J transverse
• 70<t≤100 mm: 55 J longitudinal / 37 J transverse

The ABS tables cover plates up to 150 mm. Plates thicker than 100 mm, or produced from coil, have extra rules in ABS Part 2, Chapter 1, Section 1.

ABS AH40 equivalent grades

Standard / society	Equivalent grade
ABS	AB/AH40
IACS UR W11	A40 (also written AH40)
ASTM A131	AH40
DNV	VL A40
LR / BV / CCS / RINA	AH40
NK	KA40
KR	RA40

Grades are equivalent in chemistry and properties because the IACS societies use the same unified requirements. A plate still needs a certificate from the vessel's own classification society, so one plate can carry dual or multiple class certification only when each society's surveyor tests it.

ASTM equivalent: ASTM A131 AH40 steel plate

LR equivalent: LR AH40 steel plate