S690Q Structural Steel Plate vs S690QL Alloy Steel Plate

The main difference is that S690QL has superior low-temperature impact toughness because its Charpy V-notch impact test is performed at–40°𝐶, while S690Q is tested at –20°𝐶. Both are high-strength quenched and tempered steels with a minimum yield strength of690 MPa, but S690QL is better suited for colder climates or applications requiring performance in sub-zero environments.

Both S690Q and S690QL provide a minimum yield strength of 690 MPa and a tensile strength between 770–940 MPa, depending on thickness. The major difference lies in the impact toughness testing temperature:

• S690Q is tested at 0°C, ensuring good toughness under normal temperature conditions.
• S690QL, on the other hand, is tested at –40°C, offering superior impact resistance at low temperatures.

This makes S690QL more suitable for applications in colder climates or where structures are exposed to sub-zero environments, such as offshore platforms or northern construction projects.

Both steel grades are produced using TMCP (Thermo-Mechanical Controlled Process) followed by quenching and tempering. This advanced process refines the microstructure, achieving excellent strength and weldability while maintaining toughness.

The "Q" in their names refers to the quenched and tempered process, while the "L" in S690QL indicates low-temperature impact testing compliance according to EN 10025-6 standards.

S690Q is commonly used in bridges, building structures, cranes, and general heavy machinery where high strength is required but the environment is not extremely cold.

S690QL is preferred for offshore structures, wind towers, Arctic engineering, and other low-temperature environments where resistance to brittle fracture is critical.

Both materials allow for weight reduction in structures due to their high strength-to-weight ratio, improving efficiency and reducing material costs.

S690Q and S690QL share the same strength level but differ in their toughness and temperature performance. If your project operates in normal or mild climates, S690Q offers excellent cost efficiency and mechanical strength.

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What is the difference between S690Q and S690ql?

S690Q: Minimum impact toughness tested at -20°C (30J average). → Typical Use: Cranes in temperate climates, quarry equipment. S690QL: Certified for -40°C and below (≥40J impact toughness). → Critical Use: Arctic pipelines, offshore platforms, mining vehicles in Siberia.

What is S690ql material?

S690QL steel is a high strength, low alloy structural steel that has been designed for use in heavy-duty applications such as cranes, bridges, and other structures. This steel grade is also known as Quenched and Tempered Steel, which refers to its heat treatment process.

What is the equivalent of S690ql?

S690ql is a structural high-strength grade. The ASTM En 10025 6 S690ql Equivalent Astm is the Q345 grade. The grade exhibits outstanding cold stamping and low-temperature properties.

What is the difference between S700MC and S690ql?

The S700MC Steel is basically a structural steel plate developed especially for applications requiring high yield strength. They are used for several load bearing applications. The S690ql is a low alloy structural steel which is high in strength and comes with good weldability.

What is S690QL used for?

S690QL steel plates also offer excellent resistance to abrasion and wear, making them ideal for heavy wear and tear applications. They're highly resistant to impact and sliding abrasion, making them ideal for construction equipment, mining machinery, and other industries requiring durable and dependable materials.