S690QL is a high-strength structural steel produced by quenching and tempering. The "QL" designation indicates good low-temperature toughness. It offers high strength combined with reasonable ductility and is used in heavy‑duty applications where both strength and toughness are important.
| Typical chemical composition of S690QL % Max | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
C |
SI |
Mn |
P |
S |
N |
B | Cr | Cu | Mo | Nb | Ni | Ti | V | Zr |
| 0.2 | 0.80 | 1.70 | 0.025 | 0.015 | 0.015 | 0.005 | 1.50 | 0.50 | 0.70 | 0.06 | 2.0 | 0.05 | 0.12 | 0.15 |
| Mechanical Properties of S690QL | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Designation | Mechanical Properties (ambient temperature) | ||||||||||
| Steel Name | Steel Number | Min. Yield Strength ReH MPa | Tensile Strength Rm MPa | Min. & elongation after fracture | |||||||
| Nominal thickness (mm) | Nominal thickness (mm) | ||||||||||
| >3 <50 | >50 <100 | >100 <150 | >3 <50 | >50 <100 | >100 <150 | ||||||
| S690QL | 1.8931 | 690 | 650 | 630 | 770/940 | 760/930 | 710/900 | 14 | |||
| V notch impact testing | |||||
|---|---|---|---|---|---|
|
Grade |
Sample Orientation |
at 0°C |
at -20°C |
at -40°C |
at -60°C |
| S690QL | Longitudinal | 50J | 40J | 30J | |
| S690QL | Transverse | 35J | 30J | 27J | |
applications
Heavy Transportation
S690QL is widely used in bulldozers, dump trucks, articulated haulers, trailer frames, and special vehicles. Its high strength allows significant weight reduction, which directly increases payload capacity and improves fuel efficiency, making it ideal for heavy-duty transportation applications.
Lifting & Construction Equipment
It is a preferred material for crane booms, jibs, forklift frames, hydraulic arms, and support structures for large industrial machinery. S690QL provides the high strength and toughness needed to handle heavy loads, while also helping to reduce the overall weight of the equipment.
Steel Structures
In civil engineering, S690QL is used for key components in bridges, high-rise buildings, stadiums, and offshore platforms. Its high strength enables engineers to design structures with fewer supports and longer spans, leading to more efficient and economical designs.
Machine Building
It is commonly used for frames and structural parts in industrial machinery that must withstand high fatigue and stress over long service lives. The combination of strength and toughness helps improve the reliability and durability of the equipment.
Mining & PowerS690QL is also applied in mining equipment, power plant structures, and certain types of pressure vessels. Its ability to withstand heavy loads and harsh operating conditions makes it suitable for these demanding environments.
Contact us at beam@gneesteelgroup.com. for pricing, technical support, or customized solutions. We are always ready to support your project.
What is equivalent to S690QL steel?
ASTM A514, EN 10149-2 Grade S700MC, AS/NZS 3579 Grade 700, AM 700, Bisalloy 80.
What grade is S690QL material?
S690QL is a high strength quenched and tempered steel grade that complies to steel specification EN 10025. The designation S690QL refers to a minimum yield strength of 690 MPa.
What is the price of S690ql?
₹ 130/KgS690 QL plate is a high-strength, quenched, and tempered steel plate designed for use in structural applications that require high strength and excellent toughness.
What is the maximum thickness up to which S690QL can be supplied while still maintaining its specified mechanical properties?
S690QL is commonly available in thicknesses up to around 150 mm, but the exact maximum depends on the manufacturer and the required impact toughness levels.
How does the creep resistance of S690QL compare to that of S500QL, and what operating temperature limits does this impose?
S690QL has better creep resistance than S500QL due to its higher tempering temperature and finer microstructure, but it is still not recommended for long-term service above approximately 300°C.
What is S690QL and what standard defines it?
S690QL is a quenched and tempered high-strength structural steel grade with a minimum yield strength of 690 MPa, typically defined by EN 10025-6 (or related EN standards for high-yield strength steels).
What does the "QL" in S690QL stand for?
The "Q" indicates quenched and tempered (quenched), and the "L" indicates improved low-temperature toughness compared to the non-L version (S690Q).
What are the typical minimum mechanical properties of S690QL?
S690QL typically has a minimum yield strength of 690 MPa, a tensile strength in the range of 770–940 MPa, good ductility, and specified impact toughness at low temperatures (e.g., -40°C, depending on the delivery condition and thickness).
What is the typical microstructure of S690QL?
S690QL usually has a fine-grained microstructure dominated by tempered martensite or bainite, which provides the combination of high strength and toughness.
Why is preheating often required when welding S690QL?
Preheating is often required to reduce the cooling rate in the heat-affected zone (HAZ), thereby minimizing the risk of hardening and cold cracking, especially in thicker sections or when using high-hydrogen welding processes.
What are common applications of S690QL?
S690QL is commonly used in heavy lifting equipment (e.g., crane booms), offshore structures, mining machinery, hydraulic supports, and other weight-sensitive or high-load structural components.
How does S690QL compare to S690Q?
S690QL has improved low-temperature toughness compared to S690Q. The "L" designation signifies better impact properties at lower temperatures, making S690QL more suitable for cold environments.
How does S690QL compare to S355JR?
S690QL has a much higher yield strength than S355JR (690 MPa vs. around 355 MPa), allowing for significant weight reduction in structures, but it requires more careful welding and forming due to its higher strength and lower ductility.