Abstract: 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, the bending sample is qualified.

摘要： 采用Nb、Ti、Cr、B微合金化成分,设计和开发了高品质自卸车厢体用0.20%～0.25%C耐磨钢NM450。该钢14 mm板900℃淬火200℃回火的组织为回火板条马氏体,并有少量弥散分布的第二相粒子,具有良好的综合性能。NM450钢抗拉强度1459 MPa,延伸率19%,冲击功104 J,表面硬度值450HBW。在弯曲角度为180°,弯头直径为168 mm条件下,弯曲试样合格。采用CHW-70C焊丝,焊接性能良好,焊接接头抗拉强度839MPa,焊缝冲击功113 J,焊缝硬度值282HV,在弯曲角度为90°,弯头直径为168 mm条件下,弯曲试样合格。