Properties and composition details of A572 Gr50 steel sheet

A572 Gr50 steel sheet is high-strength low-alloy niobium-vanadium structural steel plate. Execution standard ASTM A572/A572M.

Delivery status of A572 Gr50 steel sheet: hot-rolled or normalized + tempered, the specific delivery status should be indicated in the MTC.

Chemical composition of A572 Gr50 steel sheet:

Grade	C	Si	Mn	P	S	Nb
A572 Gr50	≤0.20	≤0.40	≤1.50	≤0.04	≤0.05	0.005-0.05

Influence of S and P chemical composition content on properties of A572 Gr50 steel plate:
Phosphorus (P): In general, phosphorus is a harmful element in steel, which increases the cold brittleness of steel, deteriorates welding performance, reduces plasticity, and deteriorates cold bending performance. Therefore, the phosphorus content in steel is usually required to be less than 0.045%, and the requirements for high-quality steel are lower.

Sulfur (S): Sulfur is also a harmful element in general. It makes the steel hot brittle, reduces the ductility and toughness of the steel, and causes cracks during forging and rolling. Sulfur is also detrimental to weldability, reducing corrosion resistance. Therefore, the sulfur content is usually required to be less than 0.055%, and the high-quality steel is required to be less than 0.040%. Adding 0.08-0.20% sulfur to steel can improve machinability, usually called free-cutting steel.

Mechanical properties of A572 Gr50 steel sheet:

Grade	σs，MPa	σb，MPa	δ200，%	0℃Akv，J
A572 Gr50	≥345	≥450	≥18	≥34

Note: Charpy impact test should be carried out according to customer's requirements

A572 steel sheet is divided into five grades: grade 42 (290), grade 50 (345), grade 55 (380) for riveted, bolted or welded structural parts, grade 60 (415) and grade 65 (450) for bridge riveted and bolted structural parts or welded structural parts for other purposes.