DNV Grade B Steel Plate | NV B Shipbuilding Steel Plate

NV B steel plate, also written as DNV Grade B, DNV B, VL B (newer DNV Rules designation) or NV Grade B ship steel plate, is the ordinary-strength hull structural steel of DNV Rules for Classification of Ships (IACS UR W11 ordinary-strength family) with 235 MPa minimum yield, 400-520 MPa tensile strength and Charpy V-notch toughness at 0°C [32°F]. Gangsteel, a steel plate exporter, supplies DNV NV B / Grade B 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 DNV hull structural steel rules. Official mill/certificate grade is NV B (VL B under current DNV Rules). Verify the current DNV edition before ordering.

NV B Chemical Composition (Heat Analysis)

 

Element	Heat analysis
C	0.21 max
Mn	0.80 min
Si	0.35 max
P	0.035 max
S	0.035 max

Per IACS UR W11 / DNV hull structural steel rules (ordinary-strength grades). Grade A uses a manganese minimum tied to carbon (Mn ≥ 2.5×C) and a C + Mn/6 limit of 0.40%. Grades D and E require fine-grain practice with acid-soluble Al not less than 0.015% when used as the grain-refining element.

Product Analysis (Check Analysis)

 

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 other IACS societies), unless a limit is min-only or calculated.

Element	Heat analysis limit	Product analysis (heat ± A6)
C	0.21 max	0.25 max
Mn	0.80 min	0.74 min (A6 lower)
Si	0.35 max	0.40 max
P	0.035 max	0.045 max
S	0.035 max	0.045 max

Per IACS UR W11 / DNV hull structural steel rules. Product analysis applies only when specified.

NV B Mechanical Properties

 

Grade	Yield strength, min	Tensile strength	Elongation, min
NV B	235 MPa [34 ksi]	400-520 MPa [58-75 ksi]	22%

Per IACS UR W11 / DNV hull structural steel rules. 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]	27 J	20 J
50<t≤70 mm	0°C [32°F]	34 J	24 J
70<t≤100 mm	0°C [32°F]	41 J	27 J

Per IACS UR W11 / DNV hull structural steel rules. Average of three full-size Charpy V-notch specimens when impact testing is required; not more than one value below the average and none below 70% of it. For Grade A, impact testing is typically required only above 50 mm. Thicker plates (above 100 mm) may be supplied by agreement with adjusted impact requirements.

Delivery Condition and Deoxidation

Grade B is killed steel. Delivery may be as-rolled, controlled rolled, normalized or TMCP by thickness. Optional extras by agreement include ultrasonic testing, Z-direction (Z15/Z25/Z35) through-thickness testing and third-party DNV survey.

Thickness Coverage

Ordinary-strength DNV NV A/B/D/E 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 NV B

 

Society / Standard	Equivalent grade
DNV	NV B / VL B
ABS	ABS Grade B steel plate
CCS	CCS Grade B steel plate
GL	GL Grade B steel plate
BV	BV Grade B steel plate
NK	NK Grade B steel plate
KR	KR Grade B steel plate
LR (Lloyd's Register)	LR Grade B steel plate

IACS member societies harmonize ordinary-strength hull grades under UR W11; dual certification is common when ordered that way.

FAQ about DNV Grade B / NV B Steel Plate

What is DNV Grade B (NV B) steel plate?

It is an ordinary-strength hull structural steel under DNV Rules for Classification of Ships (IACS UR W11), with 235 MPa minimum yield, 400-520 MPa tensile strength and Charpy toughness requirements at 0°C [32°F] (by thickness).

What does NV B / Grade B stand for?

NV (or VL) is the DNV grade prefix. Grade B is the ordinary-strength toughness class tested at 0°C [32°F] (impact may be waived for Grade A at t≤50 mm per UR W11).

What is the yield strength of DNV NV B?

Minimum 235 MPa (34 ksi), tensile 400-520 MPa (58-75 ksi), elongation about 22% min.

What is the impact test temperature for NV B?

Charpy V-notch at 0°C [32°F]. See the impact table for longitudinal/transverse minima by thickness band.

What is the difference between NV A, B, D and E?

Same 235 MPa ordinary-strength class. Toughness class differs: A at +20°C (often waived ≤50 mm), B at 0°C, D at -20°C, E at -40°C.

How does Grade B differ from higher-strength NV A32 / A36?

Grade B is ordinary strength (235 MPa). NV A32/A36/A40 families are higher-strength (315/355/390 MPa) under the same UR W11 framework.

Is DNV Grade B weldable?

Yes. Ordinary-strength ship plates are widely welded with standard procedures; follow approved WPS for thickness and Ceq.

What heat treatment is required for NV B?

Grade B is killed steel. Delivery may be as-rolled, controlled rolled, normalized or TMCP by thickness.

What thickness is available for DNV Grade B?

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

Other DNV Steel Plate Grades

DNV Grade A steel plate | DNV Grade D steel plate | DNV Grade E steel plate | DNV A32 steel plate | DNV A36 steel plate | DNV A40 steel plate | DNV D32 steel plate | DNV D36 steel plate | DNV D40 steel plate | DNV E32 steel plate | DNV E36 steel plate | DNV E40 steel plate | DNV F32 steel plate | DNV F36 steel plate | DNV F40 steel plate | DNV AH36 steel plate | DNV EH40 steel plate

Equivalent Class Society Grades

DNV NV B / Grade B corresponds to the same ordinary-strength grade under other IACS member classification societies: ABS Grade B steel plate, CCS Grade B steel plate, GL Grade B steel plate, BV Grade B steel plate, NK Grade B steel plate, KR Grade B steel plate, LR Grade B steel plate.