Q345-The predecessor of Q355

National standard canceled the Q345 steel grade and changed it to Q355 from February 1, 2019, which corresponds to the European standard S355. In fact, there is not much difference between Q345 and Q355, and after comparison, it is found that the tensile strength of the latter is higher.
Although the Q345 is out of the market, it still deserves special mention.

Q345 steel includes Q345A, Q345B, Q345C, Q345D, Q345E. "Q" stands for yield strength, the number 345 behind stands for the value of yield point (Unit: MPa), letters A, B, C, D, E represent the impact resistance of Q345 steel under low temperature, which mainly due to the difference in impact temperature. In short, Q345A does not do impact; Q345B does impact at 20°C (room temperature); Q345C take the impact at 0°C; Q345D does impact at -20°C; Q345E take the impact at -40°C. Different impact temperatures correspond to different impact values, the quality of grade and the code of deoxidation method can be indicated if necessary.

Their chemical composition is not much different. It is worth noting that the Al of Q345C, Q345D, and Q345E increases by 0.015, the harmful elements of P and S decrease will in turn. The temperature of the low-temperature impact test is low, and the price is relatively high.

Q345 steel has good mechanical properties, good plasticity and weldability, which is widely used in buildings, bridges, vehicles, ships, pressure vessels, etc.No matter how the product is updated, BBN can provide the products with your requirements.