S275J2 is a non-alloy structural steel plate, designated according to the European standard EN 10025-2:2019 "Hot Rolled Products of Structural Steels – Part 2: Technical Delivery Conditions for Non-alloy Structural Steels". This standard is widely adopted across the European Union and globally, enabling harmonization and mutual recognition of steel grades. As a high-grade designation within the S275 series, S275J2 combines high strength with excellent low-temperature toughness. Compared to S275JR and S275J0, it has stricter requirements for low-temperature impact performance, making it suitable for engineering applications in cold environments or under dynamic loading where exceptional resistance to brittle fracture is required.
The designation "S275J2" follows the systematic naming convention of European standards and has a clear meaning:
"S" stands for "Structural steel", indicating its structural application.
"275" denotes the specified minimum yield strength of 275 MPa. This strength level is significantly higher than that of the S235 series and comparable to China's Q275 and the US A572 Gr.50 (345 MPa), placing it in the medium-to-high strength category. It can withstand greater static and dynamic loads and is suitable for critical load-bearing components.
"J" represents the quality level for impact testing. The letter "J" indicates that Charpy V-notch impact testing is required at +20°C (room temperature).
"2" specifies the impact test temperature class. In EN 10025-2, the number "2" corresponds to a test temperature of -20°C. Therefore, the "J2" combination means the steel must undergo impact testing at -20°C, with a minimum average absorbed energy of 27 joules (J). This requirement ensures the material retains good toughness and resistance to brittle fracture in severe cold climates or low-temperature service conditions, making its performance far superior to S275JR (impact tested only at room temperature) and S275J0 (same test temperature but stricter quality control). Thus, S275J2 is an ideal material for structures in cold regions or those requiring high reliability.
The primary application of S275J2 steel plate is in manufacturing welded structural components requiring high toughness under low-temperature conditions or subjected to strong vibration and impact loads. It is widely used in cold regions such as Northern Europe, Russia, and Canada, as well as in projects with extremely high demands for structural safety and reliability. Typical applications include:
Buildings and Bridges in Cold Climates: Structures such as factories, warehouses, bridges, and towers, ensuring good impact resistance during winter and preventing low-temperature brittle fracture.
Heavy Machinery and Equipment: Frames, bases, and critical connection parts for excavators, cranes, mining machinery, and port machinery subjected to intense vibration and impact.
Transportation: Bodies and chassis for railway freight cars, container trucks, and special-purpose vehicles, to withstand dynamic stresses during operation and in cold weather.
Industrial Facilities: Attachments for cryogenic tanks, piping systems, offshore platform structures, and wind turbine towers—industrial structures with high demands on material toughness.
High-Safety-Integrity Structures: Support structures in seismic zones or for critical public facilities to enhance overall seismic and fatigue resistance.
Its main characteristics include:
Excellent Low-Temperature Impact Toughness: The "J2" requirement ensures good toughness and resistance to brittle fracture at -20°C.
Higher Strength: A minimum yield strength of 275 MPa and tensile strength exceeding 430 MPa provide strong load-bearing capacity.
Good Weldability and Workability: As a non-alloy steel, S275J2 has a moderate carbon equivalent, good weldability using conventional methods, and is easy to cut, bend, and form.
Higher Quality Requirements: Production requires strict control of chemical composition (e.g., reduced P and S content, controlled Mn content) and rolling processes to ensure qualified for the low-temperature toughness.
Balanced Cost and Performance: Although more expensive than S275JR and S275J0, it offers better economy than higher-strength grades (e.g., S355J2) while meeting medium-strength and low-temperature toughness requirements.
Ultrasonic Testing (UT)
A key non-destructive testing technique that uses high-frequency sound waves to detect internal flaws in steel plates. The probe emits sound waves, which reflect when encountering defects such as cracks or inclusions. The receiver captures the echoes, enabling precise determination of defect location and size. With high sensitivity, strong penetration, and fast inspection speed, UT effectively ensures internal quality, widely used in the production of heavy plates, pressure vessel plates, and other high-end products to guarantee safety and reliability.
Magnetic Particle Testing (MT)
A common surface inspection method that magnetizes the workpiece, causing leakage magnetic fields at surface or near-surface defects like cracks or inclusions, which attract magnetic particles to form visible indications. Simple to operate and highly sensitive, MT is suitable for rapid inspection of surface and near-surface flaws in ferromagnetic materials, widely used for online or offline inspection of plate edges, ends, and welds, ensuring product quality and safety.
Penetrant Testing (PT)
A non-destructive method for detecting surface-breaking flaws. A penetrant liquid is applied to the cleaned steel surface, allowing it to seep into defects such as cracks or pores. After removing excess penetrant, a developer is applied, causing the trapped penetrant to bleed out and form visible indications. Simple and cost-effective, PT is suitable for inspecting surface defects in various non-porous materials, commonly used for welds, castings, and complex components, effectively ensuring surface quality of steel plates.
