What is the difference between 45# steel plate and Q345 steel plate

What is the difference between 45# steel plate and Q345 steel plate?

1. Different definitions
45# steel plate: 45# steel plate is called "Quality Steel" in the Chinese standard. The 45# steel plate is pure steel and belongs to medium carbon steel plate. 45# steel plate is mainly used to manufacture mechanical structural parts with certain strength and impact resistance, such as automobile beams, beams, and frames.

Q345 steel plate: Q345 is a low-alloy steel material. Its C<0.2%, Q represents the yield strength of this material, and the latter 345 refers to the yield value of this material, which is about 345 MPa. And as the thickness of Q345 steel plate increases, its yield value decreases.

2. Different performance
45# steel plate: 45# steel has general cold plasticity, high strength and good machinability. After proper heat treatment, 45# steel plate can obtain certain toughness, plasticity and wear resistance. 45# steel plate is suitable for hydrogen welding and argon arc welding, but not suitable for gas welding. It needs preheat before welding and stress relief annealing after welding.

Q345 steel plate: it has good comprehensive mechanical properties, acceptable low temperature performance, good plasticity and weldability. Q345 steel plate is used to make dynamic loads bearing structures of medium and low pressure vessels, oil tanks, vehicles, cranes, mining machinery, power stations, bridges, etc.