"Q345b is a kind of steel. Generally at room temperature 20 degrees of temperature, impact or no test, which is a kind of low alloy steel. Q345 is widely used in Bridges, vehicles, ships, pressure vessels, special equipment, etc. The content of sulfur and phosphorus in Q345B is relatively high, which belongs to harmful elements in steel. The two elemsnts are easy to happen the embrittlement in low temperature environment, which affects the working performance. Q means the yield strength, 345 means the yield strength of this steel is 345mpa.
