摘要
应用VDA 238-100的方法和标准,通过室温拉伸试验和极限尖冷弯试验研究了铌钒复合微合金化对22MnB钢热成形钢拉伸性能和极限尖冷弯性能的影响。结果表明:铌钒复合微合金化后22MnB钢的屈服强度、抗拉强度和断后伸长率均明显提高,这与铌钒复合微合金化后晶粒尺寸和马氏体板条尺寸的减小以及铌钒碳化物的沉淀强化有关。铌钒复合微合金化后22MnB钢的极限尖冷弯角度提高20.5%,这与极限尖冷弯过程中受拉应力弯曲面的马氏体板条束细化更显著、变形协调性更好有关;铌钒复合微合金化明显提高了22MnB钢在极限尖冷弯时的最大弯曲载荷、裂纹萌生功和裂纹扩展功,改善了强韧性匹配。
The effect of Nb-V composite microalloying on the tensile properties and extreme tip cold bending properties of 22MnB hot press forming steel was studied by using the method and standard of VDA 238-100 through room temperature tensile tests and extreme tip cold bending tests.The results show that the yield strength,tensile strength and percentage elongation after fracture of 22MnB steel after Nb-V composite microalloying were significantly improved,which was related to the reduction of grain size and martensite lath size and the precipitation strengthening of Nb-V carbide after Nb-V composite microalloying.The extreme tip cold bending angle of 22MnB steel increased by 20.5%after Nb-V composite microalloying,which was related to the more significant martensite lath bundle refinement on the tensile stress bending surface and the better deformation coordination in extreme tip cold bending.Nb-V composite microalloying significantly enhanced the maximum bending load,crack initiation work and crack propagation work of 22MnB steel during extreme tip cold bending,and improved the matching of strength and toughness.
作者
马鸣图
路洪洲
刘纲
王光耀
李波
李靖伟
王启丞
MA Mingtu;LU Hongzhou;LIU Gang;WANG Guangyao;LI Bo;LI Jingwei;WANG Qicheng(China Automotive Engineering Research Institute Co.,Ltd.,Chongqing 401122,China;CITIC Metal Co.,Ltd.,Beijing 100027,China;China Railway Modern Logistics Technology Co.,Ltd.,Beijing 100081,China;China Singapore(Chongqing)Ultra High Strength Materials Research Institute Co.,Ltd.,Chongqing 401147,China;Jianlong Beiman Special Steel Co.,Ltd.,Qiqiha'er 161000,China)
出处
《机械工程材料》
北大核心
2025年第12期59-62,69,共5页
Materials For Mechanical Engineering
关键词
热成形钢
铌钒复合微合金化
极限尖冷弯性能
裂纹萌生功
裂纹扩展功
hot press forming steel
Nb-V composite microalloying
extreme tip cold bending
crack initiation work
crack propagation work
