合金元素V、Cu对含铜钢组织和性能的影响

Effect of alloying elements V and Cu on microstructure and properties of Cu-bearing steels

设计了0V1Cu钢、0.15V1Cu钢和0.15V4Cu钢3种含Cu高强钢,研究了V、Cu元素对其组织和性能的影响规律。采用相变热力学与动力学计算、LOM、SEM、TEM及显微硬度测试等系统研究了试验钢相变、显微组织和显微硬度的变化规律。结果表明:3种试验钢的Ac_(1)温度在673~675℃;添加1%Cu且V含量由0提高到0.15%时,Ac_(3)温度由769℃升高到775℃;添加0.15%V且Cu含量由1%提高到4%时,Ac3温度由775℃下降到757℃。0V1Cu钢和0.15V1Cu钢热轧态组织均为粒状贝氏体,而0.15V4Cu钢的热轧态组织为马氏体和少量贝氏体,经1100℃奥氏体化后淬火,3种试验钢组织均为板条马氏体。添加0.15%V以及V和Cu复合添加均可提高试验钢的淬火硬度。其中,0.15V4Cu钢淬火硬度(HV)最高,为597±7,与0V1Cu钢和0.15V1Cu钢相比,分别提高了44和11。以上研究表明,通过调控V和Cu的添加可以实现试验钢热轧及淬火态显微组织和显微硬度的大幅度调控,为新型超高强韧含铜钢的研发提供理论指导。

Three kinds of Cu-bearing high strength steels,namely 0V1Cu steel,0.15V1Cu steel and0.15V4Cu steel,respectively,were designed to study the effect of V and Cu elements on microstructure and properties.The phase transformation,microstructure and microhardness of experimental steels were investigated using various microstructure characterization techniques,such as LOM,SEM,TEM,along with thermodynamic and kinetic calculations.The experimental results revealed that the Ac_(1)temperature of the three steels was within the range of 673~675℃.When 1%Cu was added and V increased from 0 to 0.15%,the Ac_(3)temperature increased from 769℃ to 775℃,and with Cu increased from 1%to 4%in steel including 0.15%V,the Ac_(3)temperature decreased from 775℃ to 757℃.After hot rolling,the microstructures of 0V1Cu steel and 0.15V1Cu steel were identified as granular bainite,while 0.15V4Cu steel exhibited a microstructure consisting of martensite and a small fraction of bainite.Lath martensite was obtained in all the three steels after austenitization at 1100℃ for 5 min,followed by quenching in water.The addition of V and Cu lead to an increase in the microhardness of the Cubearing steels,with the highest microhardness(HV)of 597±7 observed in 0.15V4Cu steel,which was44 and 11 higher than 0V1Cu steel and 0.15V1Cu steel,respectively.These findings demonstrated that the microstructure and mechanical properties of the studied steels could be adjusted over a wide range by varying the amounts of V and Cu,providing valuable insights for the design of Cu-bearing steels with excellent overall performance.