S690QL Material Properties

1. High Yield Strength

The minimum yield strength can reach up to the 690 MPa grade (specific values depend on plate thickness). Compared to ordinary structural steel, S690QL can reduce structural weight and improve load-bearing efficiency while meeting design requirements.

2. Good Low-Temperature Impact Toughness

The standard Charpy V-notch impact test is conducted at -40°C, with a specified minimum energy absorption of 30 J for longitudinal specimens. Actual acceptance criteria shall be based on the applicable version of the standard, specimen orientation, and procurement technical specifications.

3. Good Balance of Strength and Toughness

A high combination of strength and toughness is achieved through quenching and tempering processes, making it suitable for structural components subjected to heavy loads. Actual fatigue performance still depends on structural design, weld quality, and the operating environment.

4. Weldable, but with controlled processes

S690QL is weldable; however, due to its high strength, it imposes strict requirements on heat input, preheating temperature, interpass temperature, and welding consumable compatibility. A qualified welding procedure (QWP) is typically required.

5. Facilitates lightweight design

Provided that design requirements for strength, stiffness, stability, and fatigue life are met, thinner plates or lighter structural configurations can be used to reduce the equipment’s weight and increase its payload capacity.