The A36 steel plate is a low-carbon steel widely used in structural applications due to its good balance of strength, weldability, and formability. Below is a detailed breakdown of its composition and properties based on ASTM A36/A36M standards:

Key Characteristics of A36 Steel

Mechanical Properties (as-rolled or normalized):

Tensile Strength: 400–550 MPa (58,000–80,000 psi)

Yield Strength: ≥250 MPa (36,000 psi) – Defines the "36" in A36.

Elongation: ≥20% (in 200 mm gauge length) – Good ductility.

Impact Toughness: Suitable for structural applications (e.g., buildings, bridges).

Weldability & Machinability:

Excellent weldability due to low carbon and controlled impurities (P, S).

Easily machined, formed, and fabricated.

Corrosion Resistance:

Basic carbon steel; requires coatings (e.g., paint, galvanizing) for corrosion protection.

Optional copper content (≥0.20%) improves rust resistance.

Comparison with Other Steels

A36 vs. 1018 Steel: A36 has higher carbon (0.20–0.29% vs. 0.18%) and looser composition limits, making it less uniform but more cost-effective for structural use.

A36 vs. A572 Grade 50: A572 has higher strength (yield ≥345 MPa) due to added microalloys (e.g., vanadium, niobium).

Common Applications

Structural frameworks (buildings, bridges)

Heavy equipment and machinery

Shipbuilding and offshore platforms

Bolts, brackets, and welded components

Note on "High Carbon" Clarification

While A36 has a higher carbon content than some mild steels (e.g., 1008), it is still classified as low-carbon steel (C ≤ 0.3%). The 0.2–0.29% carbon provides a balance of strength without compromising weldability.