Q235A Mild Steel Plate: A Versatile in Carbon Structural Steel

Q235A mild steel plate stands as one of the most widely used carbon structural steel plates in China, renowned for its balanced performance, cost-effectiveness, and adaptability across diverse industrial scenarios. Adhering to the national standard GB/T 700 (which governs rolled steels for welded structures), it serves as a reliable material solution for numerous load-bearing and structural applications.

1. Chemical Composition

• Carbon (C): 0.14% - 0.22% (Low carbon content endows the plate with excellent ductility and weldability, avoiding excessive hardness that could hinder processing).

• Silicon (Si): ≤ 0.30% (Acts as a deoxidizer during smelting, slightly enhancing strength without compromising plasticity).

• Manganese (Mn): 0.30% - 0.65% (Improves the steel’s hardenability and tensile strength while maintaining good toughness).

• Phosphorus (P): ≤ 0.045% (Strictly controlled as an impurity; excessive P can increase brittleness, especially at low temperatures).

• Sulfur (S): ≤ 0.050% (Another harmful impurity; high S content leads to "hot brittleness," which impairs welding and hot-working performance).

2. Mechanical Properties

3. Processing Performance

• Weldability: Outstanding. It can be welded using common methods such as arc welding, gas welding, and resistance welding. Weld joints exhibit high strength and low risk of cracking, making it ideal for welded structures.

• Formability: Superior. The plate can be easily bent, stamped, sheared, or rolled into various shapes (e.g., beams, channels, or custom components) without cracking or excessive deformation, thanks to its good ductility.

• Machinability: Satisfactory for general purposes. It can be processed via turning, milling, drilling, and grinding using conventional machine tools, with low tool wear and stable processing quality.

4. Typical Specifications

• Thickness: 2mm - 650mm (Thinner plates are used for light structures, while thicker ones suit heavy-duty load-bearing parts).

• Width: 1000mm - 4200mm (Custom widths can be provided by manufacturers based on orders).

• Length: 3000mm - 18000mm (Can also be supplied as coils for continuous processing lines).

5. Application Fields

• Civil Engineering & Construction: The most common application. It is used to fabricate structural components such as factory roof trusses, high-voltage transmission towers, bridge girders and columns, building frames, and steel scaffolding.

• Mechanical Manufacturing: Used for low-load mechanical parts that do not require high strength or wear resistance, such as bolts, rivets, pull rods, collars, connecting rods, and machine tool bases.

• Other Applications: Also employed in the production of containers (e.g., ordinary storage tanks), agricultural machinery, and light industrial products (e.g., steel furniture frames).

6. Key Advantages

• Cost-Effective: As a basic carbon structural steel, its raw material and production costs are low, offering high cost performance for large-scale projects.

• Versatile: Suitable for both structural and mechanical applications, covering a wide range of scenarios from civil construction to light industry.

• Stable Supply: Being a standard and widely used steel grade in China, it has mature production technology and stable supply chains, ensuring timely delivery for projects.