Chemical composition(%)

Mechanical properties

Advantages of Q355B Material:

Yield strength is approximately 50% higher than Q235, allowing for thinner cross-sections and material savings under the same load, resulting in lower overall costs. Carbon equivalent ≤0.44%, low cold cracking sensitivity, suitable for mainstream processes such as manual welding, submerged arc welding, and gas shielded welding; weld stability is achieved after preheating for thick plates.

Class B meets the requirement of ≥34J impact energy at 20℃, suitable for temperate and cold-climate outdoor structures, with superior impact and fatigue resistance compared to ordinary carbon steel. Residual Cu/Cr forms an oxide film, improving atmospheric corrosion resistance by 20%–38% compared to Q235, making it suitable for long-term outdoor use.

Good cold bending, stamping, and cutting performance; can be processed into various profiles such as steel plates, steel pipes, shaped steel, and angle steel, meeting export customization requirements.

Disadvantages of Q355B Material:

Significant thickness effect; yield strength gradient decreases after thickness >16mm. Thick plates (>63mm) require additional processing to ensure strength, increasing export processing costs.

Limited low-temperature toughness, meeting only the 20℃ impact requirement; insufficient toughness below -20℃. In extremely cold regions, Q355C/D/E grades are required, restricting exports to some areas.

Welding preheating requirements: Thick plates (>20mm) or welding in low-temperature environments require preheating to 100–150℃; otherwise, cracks are likely to occur, increasing construction/processing costs.

Alloy costs are higher than Q235. The addition of manganese and microalloying elements leads to slightly higher raw material costs, making its export price less competitive than ordinary carbon steel, but its cost-effectiveness remains superior.

Our factory's advantages in producing Q355B series products:

Our factory's advantages in producing Q235B series products:

Controllable quality, meeting export standards: We strictly adhere to GB/T 700-2006 standards, providing complete original material certificates (MTCs) for each batch to ensure compliance with export quality inspection requirements and minimal batch-to-batch quality fluctuations.

Complete specifications, adapting to diverse foreign trade needs:We can produce various common export forms such as hot-rolled coils, medium and heavy plates, flat plates, flat bars, angle bars, channel bars, round bars, and welded pipes, allowing for direct production without secondary processing by customers.

Leveraging large-scale production and a stable supply chain system:While ensuring quality, we effectively reduce production costs, resulting in strong price competitiveness, especially suitable for overseas buyers with large-volume, long-term, and stable partnerships.

Extensive experience in steel export:We are familiar with export policies and customs procedures, and can assist customers in obtaining export licenses (if required) and provide complete customs documentation. We maintain ample stock, offer flexible production scheduling, and can quickly respond to foreign trade orders. We support full container load (FCL) and less than container load (LCL) shipments, accurately controlling delivery cycles to ensure on-time arrival of goods.