Such steel in addition contain a certain amount of silicon or manganese basic elements, it also contains other elements suitable for our resources. Such as vanadium (V), niobium (Nb), titanium (Ti), aluminum (Al), molybdenum (Mo), nitrogen (N), and rare earth (RE) and other trace elements. According to chemical composition and performance requirements, the grade Q295A, B, Q345A, B, C, D, E, Q390A, B, C, D, E, Q420A, B, C, D, E, Q460C, D, E, etc. steel grade, the same meaning as carbon structural steel.