BV/D550|BV Grade D550 STEEL PLATE

BV D550 steel plate, also written as BV/D550, BV Grade D550 or market names such as DH55 / DQ56, is the extra-high-strength hull structural steel of Bureau Veritas Rules for the Classification of Steel Ships (IACS UR W16 extra-high-strength family) with 550 MPa minimum yield, 670-830 MPa tensile strength and Charpy V-notch toughness at -20°C [-4°F]. In the grade name, "D" is the toughness class, and "550" is the yield-strength level in MPa (not AH550). Gangsteel, a steel plate exporter, supplies BV D550 plates cut to size for shipbuilding, offshore platforms and marine structures.

Data source: Per IACS UR W16 (extra-high-strength hull structural steel) as adopted in Bureau Veritas hull structural steel rules, cross-checked with LR DH55 / ABS DQ56 sibling pages on gangsteel.net. Official mill/certificate grade is BV D550. Verify the current BV edition before ordering.

BV D550 Chemical Composition (Heat Analysis)

 

Element	C	Mn	Si	P	S	Al (acid sol.)
BV D550, %	0.20 max	1.70 max	0.10-0.55	0.030 max	0.030 max	0.015 min
Element	N	Nb	V	Ti	B	Notes
BV D550, %	0.020 max	0.02-0.05	0.04-0.10	0.02 max	0.005 max	Ni/Cu/Cr/Mo per delivery condition (N/TM/QT) in UR W16

Per IACS UR W16 / Bureau Veritas extra-high-strength rules. Exact maxima for Ni, Cu, Cr and Mo depend on delivery condition (N/NR, TM or QT). Carbon equivalent / CET / Pcm limits apply by thickness and condition; confirm on the mill certificate and current rule edition.

Product Analysis (Check Analysis)

 

When product analysis is required, apply ASTM A6/A6M Table A permitted variations to the heat limits unless the element is min-only or not listed in Table A.

Element	Heat analysis limit	Product analysis (heat ± A6)
C	0.20 max	0.24 max
Mn	1.70 max	see A6 Table A vs heat upper limit
Si	0.10-0.55	0.05–0.61 (approx. A6)
P	0.030 max	0.040 max
S	0.030 max	0.040 max
Al (acid sol.)	0.015 min	no A6 Table A tolerance; product value not tabulated
N	0.020 max	0.025 max (typical A6 +0.005)
Nb	0.02-0.05	0.010–0.060
V	0.04-0.10	0.030–0.110
Ti	0.02 max	0.03 max
B	0.005 max	product analysis often not applicable

Product analysis applies only when specified; for a range, results may not vary both above and below it.

BV D550 Mechanical Properties

 

Grade	Yield strength, min	Tensile strength	Elongation, min
BV D550	550 MPa [80 ksi]	670-830 MPa [97-120 ksi]	16%

Per IACS UR W16 / Bureau Veritas rules (common t≤50 mm values). Yield may step down for thicker plates per UR W16; confirm thickness-dependent values on the order.

Charpy V-Notch Impact Requirements (-20°C [-4°F])

 

Thickness	Test temperature	Longitudinal, avg min	Transverse, avg min
t≤50 mm	-20°C [-4°F]	55 J	37 J
50<t≤70 mm	-20°C [-4°F]	55 J	37 J
70<t≤100 mm	-20°C [-4°F]	55 J	37 J

Per IACS UR W16 / Bureau Veritas extra-high-strength practice. Average of three full-size specimens; transverse values apply when required. Thicker plates by agreement.

Delivery Condition and Deoxidation

Deoxidation: Killed, fine-grain practice. Delivery condition: typically TMCP or QT for extra-high-strength plates; N/NR may apply at lower extra-high levels per rules. D-class (D550) grades are typically normalized or TMCP; controlled-rolled delivery may apply within rule limits. Optional extras: UT, Z15/Z25/Z35, BV survey.

Thickness Coverage

Extra-high-strength BV A/D/E/F 420-690 plates are commonly supplied from about 6 mm to 100 mm thick (thicker by agreement under UR W16). Width 1500-4000 mm and length 6000-18000 mm are typical.

Equivalent Steel Grades of BV D550

 

Society / Standard	Equivalent grade
BV (Bureau Veritas)	BV D550 steel plate (LR DH55 / ABS DQ56)
LR (Lloyd's Register)	LR DH55 steel plate
ABS	ABS DQ56 steel plate
CCS	CCS D550 steel plate
GL	GL D550 steel plate
DNV	DNV D550 steel plate
NK	NK D56 steel plate
KR	KR D56 steel plate
RINA	RINA D550 steel plate

IACS societies align extra-high-strength hull grades under UR W16; naming differs (BV D550, LR DH55, ABS DQ56). Dual certification is common when ordered that way.

FAQ about BV D550 Steel Plate

What is BV D550 steel plate?

It is an extra-high-strength hull structural steel under Bureau Veritas Rules (IACS UR W16 extra-high-strength family), with 550 MPa minimum yield, 670-830 MPa tensile strength and Charpy toughness at -20°C [-4°F].

What does BV D550 stand for?

BV is Bureau Veritas. The letter D is the toughness class (Charpy at -20°C [-4°F]), and 550 is the yield-strength level in MPa. Market/LR naming often uses DH55; ABS often uses DQ56. Note: BV does not use AH550 — the grade is D550, not AH550.

What is the yield strength of BV D550?

Minimum 550 MPa (80 ksi), tensile 670-830 MPa (97-120 ksi), elongation about 16% min (for the common thickness range).

What is the impact test temperature for BV D550?

Charpy V-notch at -20°C [-4°F]. Typical longitudinal average minimum is 55 J (transverse 37 J) for the tabulated thickness range on this grade page.

What is the difference between BV A550, D550, E550 and F550?

Same 550 MPa strength class. Toughness class differs: A at 0°C, D at -20°C, E at -40°C, F at -60°C. Chemistry (C, P, S, Mn) is tightened for colder classes.

How does BV D550 differ from higher-strength BV AH40?

BV AH40 is UR W11 higher-strength (390 MPa). BV D550 is UR W16 extra-high-strength (550 MPa) with different chemistry and delivery practice (often TM/QT).

Is BV D550 the same as LR DH55 or ABS DQ56?

They are IACS counterparts in the extra-high-strength family; exact chemistry/delivery options differ by society edition. Dual certification is available when surveys are arranged.

Is BV D550 weldable?

Weldable with approved procedures for extra-high-strength ship steel. Preheat, heat input and consumable matching are critical; follow the mill WPS and BV welding requirements.

What heat treatment is required for BV D550?

Extra-high-strength grades are typically delivered TMCP or quenched and tempered (QT), sometimes normalized/normalized-rolled depending on strength level and thickness. D-class (D550) grades are typically normalized or TMCP; controlled-rolled delivery may apply within rule limits. Optional extras: UT, Z15/Z25/Z35, BV survey.

What thickness is available for BV D550?

Common supply is about 6-100 mm (thicker by agreement under UR W16 / BV rules), 1500-4000 mm wide and 6000-18000 mm long.

Other BV Steel Plate Grades

BV Grade A steel plate | BV Grade B steel plate | BV Grade D steel plate | BV Grade E steel plate | BV AH32 steel plate | BV AH36 steel plate | BV AH40 steel plate | BV DH32 steel plate | BV DH36 steel plate | BV DH40 steel plate | BV EH32 steel plate | BV EH36 steel plate | BV EH40 steel plate | BV FH32 steel plate | BV FH36 steel plate | BV FH40 steel plate | BV A420 steel plate | BV A460 steel plate | BV A500 steel plate | BV A550 steel plate | BV A620 steel plate | BV A690 steel plate | BV D420 steel plate | BV D460 steel plate | BV D500 steel plate | BV D620 steel plate | BV D690 steel plate | BV E420 steel plate | BV E460 steel plate | BV E500 steel plate | BV E550 steel plate | BV E620 steel plate | BV E690 steel plate | BV F420 steel plate | BV F460 steel plate | BV F500 steel plate | BV F550 steel plate | BV F620 steel plate | BV F690 steel plate

Equivalent Class Society Grades

BV D550 corresponds to extra-high-strength counterparts under other IACS societies (LR DH55, ABS DQ56, etc.): LR DH55 steel plate, ABS DQ56 steel plate, CCS D550 steel plate, GL D550 steel plate, DNV D550 steel plate, NK D56 steel plate, KR D56 steel plate, RINA D550 steel plate.