Chemical composition(%)

Mechanical properties

Advantages of SM490YA: 

Significant strength advantages: Tensile strength 490-610MPa, yield strength up to 345MPa. It belongs to low-alloy high-strength steel plates, with strength far exceeding SS400 and Q235 series. This reduces the thickness and amount of steel plates used, lowering raw material costs for customers. It is suitable for medium- and heavy-duty structural applications such as bridges, engineering machinery, and heavy equipment. Through Nb, V, and Ti micro-alloying to refine the grains, it combines high strength with good toughness and excellent plasticity, making it less prone to brittleness. Some batches contain Cr and Ni elements, resulting in better atmospheric corrosion resistance than ordinary carbon steel. It is suitable for outdoor and complex working conditions, adapting to the climates and engineering environments of Southeast Asia, the Middle East, Japan, South Korea, and other regions. Compliant with the Japanese JIS G3106 standard, SM490YA is a globally recognized low-alloy high-strength steel plate grade. It conforms to the GB standard Q355 series, European standard S355JR, and American standard A572 Gr.50, offering excellent value for money: compared to higher-strength steels like Q460 and SM520, it is more price-competitive; compared to ordinary carbon steels like SS400, its strength is significantly improved, making it suitable for large-volume procurement needs.

Disadvantages of SM490YA: 

Higher production costs: Due to the addition of microalloying elements such as Nb, V, and Ti, and the addition of corrosion-resistant elements such as Cr and Ni in some batches, the production process is more complex, resulting in higher costs than ordinary carbon steel plates like SS400 and Q235, leading to a relatively higher price. Slightly higher difficulty in cold working: After the strength increase, thicker SM490YA steel plates require greater external force during bending and stamping, making them prone to slight deformation; preheating is required in some welding scenarios. Limited corrosion resistance: Although some batches have added Cr and Ni elements to improve atmospheric corrosion resistance, there is no specific anti-corrosion design overall. It is still prone to rusting during open-air storage or sea transport, requiring anti-corrosion treatments such as painting and galvanizing for export. No impact performance requirements: Impact testing is not mandatory. Low-temperature toughness is average, making it unsuitable for extremely cold regions such as Northern Europe and Northern Russia. For extremely cold regions, the higher quality grade SM490YB is recommended.

Advantages of our factory in producing SM490YA steel plates

Our factory strictly follows the JIS G3106 standard for production, which is in line with the core requirements of the standard for SM490YA steel. At the same time, we incorporate the management concept of "same line, same standard, same quality" to ensure that the product quality meets both domestic production standards and overseas acceptance standards, and achieves the unity of domestic and foreign trade quality. Relying on mature smelting technology, we accurately control the content of basic elements such as C, Si, and Mn, strictly control the content of P and S impurities ≤0.035%, accurately add micro-alloying elements such as Nb, V, and Ti, optimize the grain structure [5], and can customize the addition of anti-corrosion elements such as Cr and Ni according to customer needs, which solves the pain point of inaccurate control of micro-alloying elements by ordinary manufacturers. Each batch of products is provided with a complete original material certificate (MTC), which clearly marks the core information such as chemical composition, mechanical properties, and furnace batch number. It can be verified by third-party testing, and the batch quality fluctuation is small, which greatly reduces the risk of inconsistent product quality.