The 0. 20% ~0. 25%C high-quality NM450 wear-resistant steel for truck compartment has been designed and developed by using Nb
Ti
Cr and B microalloying composition. The microstructure of 14 mm steel plate queched at 900 °C and tempered at 200 °C is tempered lath martensite and a small amount of dispersed second phase particles
which has the excellent comprehensive properties. The tensile strength of NM450 steel is 1 459 MPa
the elongation is 19%
the impact energy is 104 J
the surface brinell hardness value is 450HBW. With the bending angle 180°and the elbow diameter 168 mm
the bending sample is qualified. CHW-70C welding wire has good welding performance: i. e. the tensile strength of welded joint 839 MPa
the impact energy of weld 113 J
the hardness number of weld 282HV. With the bending angle 90° and the elbow diameter 168 mm