JIS G3106 SM490B Carbon and Low-alloy High-strength Steel Plate

JIS G3106 SM490B  High-strength Steel Plate Chemical Composition and Mechanical Property

Application of JIS G3106 SM490B Carbon and Low-Alloy High-Strength Steel Plate

JIS G3106 SM490B steel plate is a high-strength structural steel widely used in various engineering applications where enhanced strength, good weldability, and reliable performance under heavy loads are required. Due to its balanced mechanical properties and resistance to deformation, it is frequently selected for large-scale projects and demanding structural environments.

Common Applications Include:

Bridge Construction:
SM490B is well-suited for long-span bridges and elevated highway structures. Its high yield strength allows engineers to design lighter yet stronger structural components, improving load-bearing capacity while reducing material weight. The steel also offers good toughness, helping structures withstand wind loads, vibration, and dynamic stresses.

Highway and Transportation Infrastructure:
In highways, overpasses, and viaducts, SM490B steel plates are used to fabricate support beams, guardrails, and reinforced frameworks. Its durability ensures long service life even in outdoor exposure and variable weather conditions.

Industrial and Civil Engineering Structures:
The steel is widely used in factories, warehouses, high-rise buildings, and large public infrastructure projects. Its weldability and formability make it suitable for prefabricated structural components, improving construction efficiency and safety.

Construction Machinery and Heavy Equipment:
SM490B is often used in cranes, loaders, and lifting equipment frames where consistent strength and fatigue resistance are required. It helps ensure stable operation under repetitive load movement and impact.

Forging and Manufacturing Process of SM490B Steel Plate

Although SM490B steel is commonly supplied as rolled steel plate, forging or thermomechanical processing may be used in certain manufacturing requirements to optimize mechanical properties.

Forging / Manufacturing Process Overview:

Raw Material Selection:
High-quality carbon and low-alloy elements are selected and proportioned to ensure uniform composition. Elements like Mn and Si enhance strength and toughness.

Heating:
The steel billet is heated to a controlled temperature range (usually 1100°C–1250°C) to allow proper plastic deformation without cracking. Precise temperature control is essential to maintain grain structure.

Forging / Rolling:
The heated billet is pressed or rolled to the required thickness and shape. This process refines the internal grain structure, improving strength, toughness, and overall mechanical uniformity.

Normalizing / Controlled Cooling:
After forming, the steel is cooled under controlled conditions or normalized. This step helps eliminate internal stress and enhances structural stability, ensuring the product maintains consistent performance during use.

Final Inspection:
Non-destructive testing (NDT), chemical composition analysis, and mechanical property testing are conducted to meet JIS G3106 standards.