RINA Grade B Shipbuilding Steel Coil
RINA Grade B Shipbuilding Steel Coil: Comprehensive Material Data, Properties, and Global Equivalents
Explore detailed material data for RINA Grade B shipbuilding steel coil including chemical composition, mechanical and thermal properties, international equivalent grades, and application guidance.
Hot rolling, controlled rolling, normalizing, cold forming, welding, cutting, bending
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RINA Grade B Shipbuilding Steel Coil Introduction
RINA Grade B is a normal strength hull structural steel as per the rules of Registro Italiano Navale (RINA), suitable for shipbuilding and marine structures. It belongs to the IACS (International Association of Classification Societies) ordinary-strength steel group, offering a minimum yield strength of 235 MPa, good weldability, and moderate toughness. This steel is commonly supplied in coil or plate form, used for hull plates, stiffeners, and structural components. It meets the requirements of RINA Part D, Chapter 1 for Grade B steel. The steel is produced through controlled rolling or normalizing processes to ensure consistent mechanical properties and grain refinement. Its chemistry is balanced to provide adequate strength and excellent formability, making it a cost-effective choice for various marine applications.
RINA Grade B Shipbuilding Steel Coil Chemical Composition
The chemical composition of RINA Grade B steel is defined according to RINA Rules and IACS UR W11. Key elements are controlled to ensure strength, weldability and toughness. Grain-refining elements such as aluminium are typically added. Optional microalloying with niobium, vanadium or titanium may be used. Typical limits are shown below.
| Element | Standard Value (max, unless range given) | Remarks |
|---|---|---|
| Carbon (C) | ≤ 0.21 | Also per ladle analysis |
| Manganese (Mn) | ≥ 0.60 (≥ 2.5 × C) | Typical 0.60–1.00 |
| Silicon (Si) | ≤ 0.35 | Deoxidation practice |
| Phosphorus (P) | ≤ 0.035 | |
| Sulfur (S) | ≤ 0.035 | |
| Aluminium (Al, total) | ≥ 0.015 | When used as grain refiner |
| Niobium (Nb) | 0.02–0.05 | Optional microalloy |
| Vanadium (V) | 0.05–0.10 | Optional microalloy |
| Titanium (Ti) | ≤ 0.02 | Optional microalloy |
RINA Grade B Shipbuilding Steel Coil Thermal and Electrical Physical Properties
Physical properties are typical for carbon‑manganese structural steels and are not part of the RINA acceptance criteria. They are provided as engineering reference data for design calculations. Values may vary slightly with temperature and exact composition.
| Property | Typical Value | Unit | Condition / Remarks |
|---|---|---|---|
| Density (ρ) | 7.85 | g/cm³ (7850 kg/m³) | At room temperature |
| Elastic modulus (E) | 205 | GPa | Static loading, typical carbon steel |
| Shear modulus (G) | ≈ 80 | GPa | Calculated from E and Poisson ratio |
| Poisson's ratio (ν) | 0.30 | – | In the elastic range |
| Thermal expansion coefficient (α) | 11.7 | 10⁻⁶/K | 20–100 °C |
| Thermal conductivity (λ) | 51.9 | W/(m·K) | At 100 °C |
| Specific heat capacity | 486 | J/(kg·K) | At room temperature |
| Electrical resistivity (ρₑ) | 0.142 | μΩ·m | At 20 °C |
RINA Grade B Shipbuilding Steel Coil Mechanical Properties
Mechanical properties are specified for delivery condition. Requirements are based on test pieces taken in the rolling direction (longitudinal) or transverse direction. Impact energy values are guaranteed at 0 °C. Bend test ensures adequate formability without cracking.
| Property | Required Value | Unit | Test Condition / Remarks |
|---|---|---|---|
| Yield strength (ReH) | ≥ 235 | MPa | Thickness ≤ 100 mm |
| Tensile strength (Rm) | 400 – 520 | MPa | Thickness ≤ 100 mm |
| Elongation (A) | ≥ 22 | % | L₀ = 5.65√S₀; thickness ≤ 50 mm |
| Elongation (A) | ≥ 21 | % | L₀ = 5.65√S₀; thickness > 50–70 mm |
| Elongation (A) | ≥ 20 | % | L₀ = 5.65√S₀; thickness > 70–100 mm |
| Bend test | 180°; d = 3a | Thickness ≤ 25 mm; no cracks | |
| Bend test | 180°; d = 4a | Thickness > 25–100 mm; no cracks | |
| Impact energy (KV₂) longitudinal | ≥ 27 | J | At 0 °C |
| Impact energy (KV₂) transverse | ≥ 20 | J | At 0 °C |
RINA Grade B Shipbuilding Steel Coil Fully Equivalent Material Standards and Substitutable Grades
| Country / Region | Standard | Grade | Remarks |
|---|---|---|---|
| Italy / RINA | RINA Rules | Grade B | Identical – based on IACS UR W11 |
| USA / ABS | ABS Rules | Grade B | Identical |
| France / BV | BV Rules | Grade B | Identical |
| China / CCS | CCS Rules | Grade B | Identical |
| Norway / DNV | DNV Rules | Grade B | Identical (now DNV GL) |
| UK / LR | LR Rules | Grade B | Identical |
| Japan / NK | NK Rules | Grade B | Identical |
| South Korea / KR | KR Rules | Grade B | Identical |
| Russia / RS | RS Rules | Grade B | Identical |
RINA Grade B Shipbuilding Steel Coil Application Introduction
RINA Grade B steel coil is a primary material for marine and offshore construction. Its balanced strength and weldability allow efficient fabrication of large welded structures. The coil form is particularly suitable for continuous processing into longitudinally stiffened panels, corrugated bulkheads, and deck profiling lines. After uncoiling, the steel can be cut, formed, and welded to produce ship sub‑assemblies. Common processing includes
- Plasma or laser cutting of hull panels and stiffeners
- Cold forming of frames and brackets
- Autonomous and robotic welding of stiffened panels
- Shot‑blasting and painting for corrosion protection
Product Applications: Ship hull plates, Weather decks, Transverse and longitudinal bulkheads, Hatch coamings and covers, Superstructure panels, Main deck stringers
Processed into products: Shell plating panels, Longitudinals and transverse frames, Web frames and stiffeners, Floor plates and brackets, Girders and beams, Pillar and stanchion bases
Application industries: Shipbuilding and repair, Marine engineering, Offshore platform construction, Barge and pontoon manufacturing, Port and harbour structure fabrication
RINA Grade B Shipbuilding Steel Coil Closest / Similar Alternative Material Recommendations
| Country / Region | Standard | Grade | Remarks |
|---|---|---|---|
| USA | ASTM A131/A131M | Grade B | Shipbuilding steel; yield ≥235 MPa, tensile 400–490 MPa; verify impact test temperature (usually 0 °C) |
| European Union | EN 10025-2 | S235JR (+N) | Structural steel with similar yield strength; check toughness and welding requirements for marine application |
| Japan | JIS G3106 | SM400A / SM400B | Weldable structural steel; SM400B offers 0 °C impact guarantee; yield ≥245 MPa for thickness ≤16 mm |
Notes:
This data reflects RINA Rules published by the Registro Italiano Navale and the IACS UR W11 requirements. For design purposes, always refer to the latest edition of the applicable classification society rules. The physical property values are approximate and may vary with temperature, thickness, and specific production route.
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