NK/K A32|NK A32 STEEL PLATE

NK A32 steel plate, also written as KA32, K A32, ClassNK A32, NK Grade A32 or market name AH32, is the higher-strength hull structural steel of ClassNK (Nippon Kaiji Kyokai) Rules for the Survey and Construction of Steel 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, and "32" refers to the strength level (historically about 32 kgf/mm²); ClassNK mill certificates commonly use the K prefix (KA32), while AH32 is the common IACS market name with "H" for higher strength. Gangsteel, a steel plate exporter, supplies NK A32 / KA32 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 ClassNK hull structural steel rules. Official mill/certificate grade is typically KA32 (K A32); NK A32 and AH32 name the same class on this site. Verify the current ClassNK edition before ordering.

NK A32 / KA32 Chemical Composition (Heat Analysis)

Per IACS UR W11 / ClassNK (NK) hull structural steel rules (higher-strength grades). 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 (%).

Product Analysis (Check Analysis)

IACS UR W11 / ClassNK rules 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 other IACS societies).

Per IACS UR W11 / ClassNK hull structural steel rules. Product analysis applies only when specified; for a range, results may not vary both above and below it.

NK A32 / KA32 Mechanical Properties

Per IACS UR W11 / ClassNK 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])

Per IACS UR W11 / ClassNK hull structural steel rules. 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. Thicker plates (above 100 mm) may be supplied by agreement with adjusted impact requirements.

Delivery Condition and Deoxidation

Deoxidation: Killed, fine-grain practice. Delivery condition: A-class (K A32 / AH32) 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 ClassNK survey.

Thickness Coverage

Higher-strength NK A/D/E/F 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 NK A32

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

FAQ about NK A32 / KA32 Steel Plate

What is NK A32 (KA32) steel plate?

It is a higher-strength hull structural steel under ClassNK (Nippon Kaiji Kyokai) Rules for the Survey and Construction of Steel Ships (IACS UR W11), with 315 MPa minimum yield, 440-590 MPa tensile strength and Charpy toughness at 0°C [32°F]. The mill certificate grade is typically KA32 (K A32); NK A32 and market name AH32 refer to the same strength/toughness class.

What does NK A32 / KA32 / AH32 stand for?

NK (ClassNK) is Nippon Kaiji Kyokai. The K prefix on the mill grade (KA32) is the ClassNK designation. The letter A is the toughness class (Charpy at 0°C [32°F]), and 32 is the strength level (historically about 32 kgf/mm², now 315 MPa min yield). AH32 adds "H" for higher strength in common IACS market naming.

What is the yield strength of NK A32?

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

What is the impact test temperature for NK A32 / KA32?

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 NK A32 and other 32-class grades?

Same 315 MPa strength class. NK A32 (KA32) at 0°C [32°F]; NK D32 (KD32) at -20°C [-4°F]; NK E32 (KE32) at -40°C [-40°F]; NK F32 (KF32) at -60°C [-76°F]. Delivery condition follows the toughness letter rules.

What is the difference between NK A32 and NK A36?

Same A-class toughness (Charpy at 0°C [32°F]). NK A32 is strength class 32 (315 MPa min yield); NK A36 is strength class 36 (355 MPa min yield).

Is NK A32 the same as ABS AH32 or LR AH32?

Requirements are essentially harmonized under IACS UR W11. ABS AH32, LR AH32, DNV A32, BV AH32 and ASTM A131 AH32 (where listed) are counterparts; dual certification is common when ordered with the required surveys.

Is NK A32 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 NK A32?

A-class (K A32 / AH32) grades may be as-rolled, controlled rolled, normalized or TMCP depending on thickness; thicker plates usually N or TMCP.

What thickness is available for NK A32?

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

Other NK Steel Plate Grades

NK Grade A steel plate | NK Grade B steel plate | NK Grade D steel plate | NK Grade E steel plate | NK A36 steel plate | NK A40 steel plate | NK D32 steel plate | NK D36 steel plate | NK D40 steel plate | NK E32 steel plate | NK E36 steel plate | NK E40 steel plate | NK F32 steel plate | NK F36 steel plate | NK F40 steel plate

Equivalent Class Society Grades

NK A32 / KA32 (AH32) corresponds to the same grade under the other IACS member classification societies and ASTM A131: LR AH32 steel plate, ABS AH32 steel plate, CCS AH32 steel plate, ASTM A131 AH32 steel plate, GL AH32 steel plate, DNV A32 steel plate, BV AH32 steel plate, KR A32 steel plate, RINA AH32 steel plate.