Q620D steel plate belongs to quenched and tempered high-strength plate, and Q620D steel plate implements GB/T16270-2009 standard. In the Q620D steel plate, Q stands for the initial letter of the steel plate yield, 620 stands for the yield strength of the steel plate, and C/D/E/F stands for the impact temperature.
1. Defects such as cracks, bubbles, folds and inclusions are not allowed on the surface of the steel plate. Steel plates shall not have delamination.
For the above-mentioned defects, cleaning is allowed, and the cleaning depth is calculated from the actual size of the steel plate, and shall not be greater than half of the thickness tolerance of the steel plate, and the minimum thickness of the steel plate shall be guaranteed. Defect cleaning should be smooth without edges and corners.
2. Other defects are allowed, but the depth is calculated from the actual size of the steel plate, and shall not exceed half of the allowable thickness tolerance, and it shall be ensured that the thickness of the defect does not exceed the allowable minimum thickness of the steel plate.
3. After negotiation between the supplier and the buyer and specified in the contract, welding repair is allowed for the steel plate. If welding repair is carried out after quenching and tempering treatment, quenching and tempering treatment shall be carried out again.
4. After negotiation between the supplier and the buyer and specified in the contract, the surface quality can be in accordance with the provisions of GB/T 14977.
