S690Q High Strength Structural Steel Plate

1. What is S690Q High Strength Structural Steel Plate?

S690Q high-strength structural steel plate is a fine-grained, high-strength structural steel plate that complies with the European standard EN 10025-6; its material number is 1.8931.

S690Q high-strength structural steel plate is quenched and tempered (Q+T) and features a high yield strength (≥ 690 MPa), good impact toughness (impact energy absorption ≥ 30 J at -20°C), good weldability, and comprehensive mechanical properties suitable for engineering and manufacturing applications.

S690Q high-strength structural steel plates are primarily used in engineering equipment and steel structures that demand high structural strength, load-bearing capacity, and lightweight design, such as heavy-duty construction machinery, lifting equipment, excavators, mining machinery, mining engineering vehicles, high-load steel structures, and heavy-duty load-bearing components.

We supply S690Q high-strength structural steel plates in a full range of specifications, accompanied by Material Test Certificates (MTCs), and support third-party inspections. We also offer services such as custom sizing, precision cutting, acid pickling, shot blasting, and anti-corrosion coatings.

2. Meaning of the Grade Designation “EN10025-6 S690Q”

1. The chemical composition achieves a balance of high strength and toughness through alloying elements (such as Cr, Mo, Ni) and microalloying elements (Nb, V, Ti), while controlling the content of harmful elements (P, S).

2. Cr and Mo enhance hardenability and strength; Ni improves low-temperature toughness; Nb, V, and Ti refine the grain structure, increasing strength and toughness; low P and S reduce inclusions and decrease brittleness.

Thickness influence: When the plate thickness exceeds 16mm, a reasonable reduction in yield strength is allowed (e.g., ReH ≥ 650MPa for thicknesses of 50-100mm). Specific values should be referenced according to the standard or the steel mill’s quality assurance certificate.

1. High yield strength and outstanding load-bearing capacity

The high strength enables the material to withstand large structural loads, making it suitable for heavy-duty engineering structures.

2. Contributes to structural weight reduction

It allows for a reduction in the thickness or quantity of steel required for certain load-bearing components, thereby lowering the equipment’s dead weight, improving payload utilization, and helping to reduce transportation and operating costs.

3. Quenched and tempered treatment, with excellent overall mechanical properties

The combination of quenching and tempering processes achieves the required balance of strength and toughness, making it suitable for engineering applications with high demands on structural load-bearing capacity and reliability.

4. Suitable for Heavy-Duty and High-Demand Engineering Structures

It can be used in crane booms, excavator working mechanisms, load-bearing components of mining machinery, heavy-duty transport equipment, and other applications requiring high-strength structural materials, helping to enhance the compactness and load-bearing efficiency of structural designs.

5. Potential for Engineering Machining and Welding Applications

It can be cut, grooved, formed, and welded according to product specifications and process requirements.

Due to its high strength, heat input, preheating temperature, welding materials, and necessary post-welding treatments must be carefully controlled during manufacturing to prevent cold cracks and a decline in the properties of the heat-affected zone.

6. Wide Range of Applications and Good Overall Economic Benefits

Suitable for construction machinery, mining equipment, heavy-duty vehicles, lifting and transportation equipment, and certain large-scale steel structures.

Through appropriate material selection and structural optimization, it is possible to reduce material consumption and the full life-cycle cost of equipment while meeting design requirements.

1. Cranes and Heavy-Duty Lifting Equipment

Key application areas for S890QL1 include the telescoping booms of truck cranes, the booms of crawler cranes, port cranes, offshore lifting equipment, and heavy-duty lifting assemblies.

2. Construction Machinery

Suitable for load-bearing components in large excavators (boom and dipper), concrete pump truck outriggers, pile-driving machinery, aerial work platforms, and other heavy-duty construction equipment.

3. Mining Machinery and Heavy-Duty Equipment

Suitable for load-bearing structures of mining dump trucks, structural components of large loaders, frames of mining transport equipment, and support components of heavy machinery.

4. Heavy-Duty Transport Vehicles and Special-Purpose Vehicles

Suitable for chassis and load-bearing components of heavy-duty trailers, low-bed semi-trailers, special-purpose transport vehicles, and certain heavy-duty vehicles.

5. Offshore Engineering and Equipment for Cold Regions

Applicable to certain offshore lifting equipment, port loading and unloading machinery, construction machinery for cold regions, and heavy-duty load-bearing structures in low-temperature environments.

6. Wind Power and Energy Equipment

Applicable to lifting equipment on wind turbine installation vessels, auxiliary machinery for wind turbine installation, frames for large-scale energy equipment, and heavy-duty maintenance devices.

Precautions for Procurement and Use

1. Clearly Define Technical Requirements

During procurement, specify thickness, width, length, impact temperature (Q/-20°C or QL/-40°C), surface condition, and additional inspection requirements (such as non-destructive testing and Z-direction properties).

2. Welding Process Control

Preheating is required before welding (recommended preheating temperature: 80-150°C, depending on plate thickness) to avoid cold cracks. Stress relief heat treatment (e.g., 600-650°C tempering) can be performed after welding.

3. Tool Selection for Machining

Due to high strength, use carbide tools (e.g., WC-Co alloy), reduce cutting speed, and increase feed rate to minimize tool wear.

4. Verification of Quality Certificate

Ensure the steel mill provides a quality certificate compliant with EN 10204 Type 3.1, confirming compliance with chemical composition, mechanical properties, heat treatment status, and other indicators.

Summary

EN 10025-6 S690Q is a premium, ultra-high-strength structural steel offering an exceptional strength-to-weight ratio.

Its use allows for lighter and more efficient designs but demands a high level of expertise and controlled procedures during fabrication, especially welding.

• S690Q Equivalent Materials