What is S690Q material？

What is S690Q material?

S690Q  is a high-strength, low-alloy structural steel, known for its exceptional strength (minimum 690 MPa yield strength) achieved through quenching and tempering, making it ideal for heavy-duty applications like cranes, bridges, and mining equipment where weight reduction and high load capacity are crucial. Its designation breaks down as S (Structural), 690 (MPa minimum yield), and Q (Quenching & Tempering), with 'L' indicating low-temperature impact toughness.

S690Q is a high-strength low alloy (HSLA) steel that conforms to the EN 10025-6 and DSTU EN 10025-6 standards. It is a hot-rolled hardened structural steel that has undergone subsequent tempering treatment to achieve its superior mechanical properties.

The corrosion resistance of S690Q is mainly influenced by the carbon content and alloying elements. Due to its low carbon content, S690Q has good corrosion resistance, especially in atmospheric environments and moderately corrosive media. However, in more corrosive environments, appropriate anti-corrosion measures may be required to improve its corrosion resistance.

Understanding its composition is key to its performance, as S690Q is a high-strength low alloy steel with excellent properties. Because of these characteristics, it is widely used in various engineering fields, such as:

Construction

Bridges

Machinery

Pressure Vessels

Technical Requirements & Additional Services for S690Q steel plate:
♦ Low temperature impacting test
♦ Quenching and Tempering heat treatment
♦ Ultrasonic test under EN 10160,ASTM A435,A577,A578
♦ Issued Orginal Mill test certificate under EN 10204 FORMAT 3.1/3.2
♦ Shot blasting and Painting,Cutting and welding as per end user's demands

What are Common Testing Requirements of S690Q ?

Common testing requirements for S690Q high-strength steel, governed by EN 10025-6 standard, focus on mechanical properties (yield strength, tensile strength, elongation), low-temperature Charpy V-notch impact toughness at -20°C, and require Quenching and Tempering (Q+T) heat treatment, with supplementary tests like Ultrasonic Testing (UT) often included, and Mill Test Certificates (MTC) provided.

What is the composition of S690Q ?

S690Q is a high-strength, low-alloy steel (HSLA) defined by the EN 10025-6 standard, known for its 690 MPa yield strength after quenching and tempering, featuring controlled levels of Carbon (≤0.22%), Silicon (≤0.80%), Manganese (≤1.8%), with strengthening microalloying elements like Niobium, Vanadium, Titanium, Chromium, Molybdenum, and Nickel, ensuring good weldability for heavy-duty applications like bridges, cranes, and construction equipment.

What is the hardness of S690Q ?

The hardness of S690Q steel typically falls in the range of 228-278 HBW (Brinell Hardness) for thicknesses up to 50mm, and slightly lower, 225-276 HBW, for thicker plates (over 50mm to 100mm), reflecting its high-strength, quenched and tempered (Q+T) condition. This range provides a balance of strength (minimum yield of 690 MPa) and toughness for demanding structural applications.

Chemical composition % of steel S690Q (1.8931): EN 10025-6-2004

Mechanical properties of S690Q steel

Analogues to S690Q steel

1What is S690Q equivalent to material?

S690Q is a high-yield strength structural steel (EN 10025-6) with equivalents like ASTM A709 Grade 100, German TStE690V (DIN), French E690T (AFNOR), and proprietary grades such as DILLIMAX 690, NAXTRA 70, and WELDOX 700, all characterized by minimum 690 MPa yield strength and excellent toughness after quenching and tempering (Q&T) for heavy load applications. The "L" in S690QL signifies lower-temperature impact testing (-40°C) for enhanced cold-weather toughness,

2What temperature is S690Q?

S690Q is a high-strength, quenched and tempered structural steel (governed by the EN 10025-6 standard) characterized by a minimum yield strength of 690 MPa and guaranteed impact toughness at temperatures as low as -20°C. It is primarily utilized in heavy-duty applications such as mining equipment, cranes, and bridge construction, where a high strength-to-weight ratio and excellent weldability are required.

3What are the primary advantages of this S690Q ?

The primary advantages of S690Q steel are its extremely high strength (690 MPa yield), enabling lighter, leaner structures with reduced material use, and its excellent toughness, even at low temperatures, making it ideal for heavy-duty applications like cranes, bridges, and offshore structures, while also offering good fatigue resistance and weldability for demanding conditions.

4What are the typical application fields of S690Q ?

S690Q is a high-strength structural steel used in applications requiring excellent strength-to-weight ratios, such as bridges, cranes, offshore platforms, heavy machinery, and high-rise buildings, allowing for lighter yet robust designs in construction and industrial equipment, especially where high stress and demanding conditions (like low temperatures) are present.

5What precautions should be taken when welding of S690Q ?

When welding S690Q high-strength steel, key precautions include using low-hydrogen consumables, controlling heat input and interpass temperatures, ensuring adequate preheating and potentially post-heating, maintaining cleanliness, and wearing proper PPE to prevent cracking, hydrogen embrittlement, and mechanical property degradation. Specific procedures depend on plate thickness, but controlling cooling rate is critical for this quench-and-tempered steel.

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