BV Grade A steel chemical and mechanical properties

BV Grade A steel is a general-purpose structural steel used in the shipbuilding industry, and it is subject to the specifications set by Bureau Veritas (BV), a classification society. The specification for BV Grade A is in line with other similar shipbuilding steel grades, such as ASTM A131 Grade A and LR A, with particular properties and requirements for welding and toughness at lower temperatures.

Here’s a summary of the BV Grade A shipbuilding steel specification:

1. Chemical Composition:
The chemical composition of BV Grade A steel typically includes:

Carbon (C): ≤ 0.18%
Manganese (Mn): 0.60% – 1.00%
Silicon (Si): ≤ 0.50%
Phosphorus (P): ≤ 0.035%
Sulfur (S): ≤ 0.035%
Copper (Cu): ≤ 0.25%
Nickel (Ni): ≤ 0.40% (optional, depending on the specification and grade)
The steel is designed for excellent welding properties, strength, and durability in marine environments.

2. Mechanical Properties:
Yield Strength: ≥ 235 MPa (megapascals) for thicknesses up to 50mm.

Tensile Strength: 400 MPa – 520 MPa.

Elongation: ≥ 20% in 200mm (depends on thickness).

Impact Toughness:
BV Grade A steel is required to meet a certain level of impact toughness, particularly for applications in low-temperature conditions. The typical Charpy V-notch impact tests (at 0°C or 20°C) should meet a value of:

Longitudinal Impact Value (Charpy V-notch): ≥ 27 J at 0°C (depending on thickness).
Thickness: BV Grade A steel is available in thicknesses from 6mm to 50mm (and even up to 100mm in certain cases), depending on the requirement of the project.