Nb、Ti微合金化Q345R压力容器板性能研究

Study on Properties of Nb-Ti Micro-alloyed Hot Continuous Rolling and Conventional Rolling Q345R Pressure Vessels Steel Plates

对比研究了中厚板轧制Q345R及TMCP热连轧工艺下Nb、Ti微合金化处理的Q345R压力容器钢板的力学性能,分析了Nb、Ti微合金化的影响及显微组织与性能之间的关系。结果表明:低碳、Nb-Ti微合金处理的热连轧钢板组织细小均匀,消除了带状偏析,材料的冲击韧度提高2～3倍,断裂韧性较好,钢板的综合性能明显好于中厚板。晶粒细化及组织均匀化是材料韧性大幅度提高的主要原因。

The mechanical properties of Q345R pressure vessels steel produced by different technology such as conventional process and hot continuous rolling were studied.The effects of Nb-Ti micro-alloyed on properties and relationship between microstructure and properties were analyzed.The results show that the microstructure of Nb-Ti micro-alloyed hot continuous rolling plates can be refined and pearlite segregation band in matrix disappears,so,the impact energy and fracture toughness of the steel increase greatly and synthetics properties of the steel improve.The reason for performance improvement of the steel is microstructure refining and homogenization.