Description of Rectangular Pipe Q215 Rectangular pipe Q215 is a type of carbon steel structural pipe with a rectangular cross-section, widely used in construction, machinery, and industrial applications. It is manufactured from Q215 steel, a low-carbon steel grade known for its good strength, weldability, and formability. The "Q" in Q215 stands for yield strength (Qu in Chinese), and "215" indicates the minimum yield strength of 215 MPa. Material Properties Q215 steel is a general-purpose carbon steel with the following key characteristics: - Low Carbon Content: Typically around 0.10–0.15%, ensuring good ductility and ease of welding. - Yield Strength: Minimum 215 MPa, providing adequate structural support. - Tensile Strength: Ranges between 335–450 MPa, offering a balance between strength and flexibility. - Elongation: Approximately 26–31%, indicating good deformation resistance before fracture. - Corrosion Resistance: Basic corrosion resistance, though surface treatments (e.g., galvanization or painting) may be applied for enhanced durability. Manufacturing Process Rectangular pipes are produced through two primary methods: 1. Welded Process: Steel coils or plates are cold-formed into a rectangular shape and welded along the seam (ERW or HFW methods). 2. Seamless Process: Less common for rectangular pipes, involving hot extrusion for seamless construction. Dimensions and Specifications - Common sizes range from small (e.g., 20×10 mm) to large (e.g., 200×100 mm) with varying wall thicknesses (1.5–12 mm). - Standard lengths: 6 meters or customized per requirements. - Tolerances comply with international standards (e.g., ASTM, EN, or GB). Applications Due to its structural efficiency, Q215 rectangular pipe is used in: - Construction: Frames, supports, and scaffolding. - Automotive: Chassis and roll cages. - Furniture: Metal frames for tables, shelves, and cabinets. - Infrastructure: Guardrails, signage, and drainage systems. Advantages - Lightweight yet strong, ideal for load-bearing structures. - Easy to fabricate, cut, and weld. - Cost-effective compared to higher-grade steels. Limitations - Lower corrosion resistance than stainless steel; requires protective coatings in harsh environments. - Not suitable for high-stress applications requiring high yield strength. Conclusion Rectangular pipe Q215 is a versatile and economical choice for structural and mechanical applications, offering a balance of strength, workability, and affordability. Proper selection based on environmental conditions and load requirements ensures optimal performance. (Word count: 500)