Q390GJB is a high-strength, low-alloy steel plate primarily used in engineering, construction, machinery, and other fields. Regarding the performance indicators of Q390GJB steel plate, the following are its main performance metrics and related characteristics:

1. Strength: Q390GJB steel plate has high strength, with a yield strength of 390 MPa and a tensile strength of 500 MPa. This gives the steel plate good resistance to yielding under heavy loads and deformation.

2. Toughness: Q390GJB steel plate exhibits good toughness and excellent impact resistance. Even in low-temperature environments, its toughness and impact resistance remain high, which helps improve the seismic performance of steel structures.

3. Plasticity: Q390GJB steel plate has good plasticity and excellent workability. During processing, the steel plate is less prone to defects such as cracks and burrs, which helps enhance processing quality and efficiency.

4. Weldability: Q390GJB steel plate has good weldability and is suitable for various welding methods. During welding, the deposited metal of the steel plate exhibits high plasticity and toughness, ensuring stable weld performance.

5. Corrosion Resistance: Q390GJB steel plate has certain corrosion resistance, but in corrosive environments, anti-corrosion measures are still required. Typically, a layer of anti-corrosion coating is applied to the surface of the steel plate to extend its service life.

6. Dimensional Accuracy: Q390GJB steel plate has high dimensional accuracy, with thickness, width, and length deviations all within national standards. This helps improve the installation precision and operational performance of steel structures.

7. Applications: Q390GJB steel plate is widely used in bridges, pressure vessels, heavy machinery, building structures, and other fields. Under the requirements of high strength and low alloy content, Q390GJB steel plate can meet the needs of various engineering and mechanical structures.

In summary, Q390GJB steel plate has high strength, toughness, plasticity, and other performance metrics, as well as good weldability and corrosion resistance. With appropriate anti-corrosion measures, Q390GJB steel plate can be widely used in various engineering and mechanical fields. However, for more detailed performance data and application examples of Q390GJB steel plate, it is necessary to refer to relevant standards and technical specifications.