V-N微合金化热轧因瓦合金的组织和性能  

Microstructure and properties of V-N microalloyed hot-rolled invar alloy

作　　者：刘慧 于彦冲[1] 奉亮 孙中华 张金玲[1] LIU Hui;YU Yan-chong;FENG Liang;SUN Zhong-hua;ZHANG Jin-ling(College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;HBIS Group Material Technology Research Institute,Shijiazhuang 052165,China)

机构地区：[1]太原理工大学材料科学与工程学院,山西太原030024 [2]河钢材料技术研究院,河北石家庄052165

出　　处：《材料热处理学报》2024年第8期127-135,共9页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(52004180,52204350);中国博士后科学基金(2020M683706XB);山西省回国留学人员科研资助项目(2023-080)。

摘　　要：因瓦合金具有极低的热膨胀系数,但较低的力学强度严重制约其在结构材料领域的应用。为进一步提升因瓦合金的强度,借鉴微合金化思想,设计了V-N微合金化因瓦合金。采用维氏硬度计、拉伸试验机、电子背散射衍射(EBSD)、X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)等研究了微量V、N对热轧因瓦合金显微组织和力学性能的影响,并分析其作用机理。结果表明:V-N微合金化因瓦合金的热轧组织显著细化,硬度和抗拉强度显著增加;随着N含量增加,其晶粒尺寸进一步细化,且分布更为均匀,抗拉强度进一步增加。V-N微合金化因瓦合金的基体上析出了大量细小、弥散分布的V(C,N)第二相,尺寸约为400 nm,其钉扎晶界和位错。细晶强化、析出强化和位错强化是V-N微合金化因瓦合金力学性能显著提升的主要原因。Invar alloys have an extremely low coefficient of thermal expansion,but their low mechanical strength seriously restricts their application in the field of structural materials.In order to further enhance the strength of the invar alloys,V-N microalloyed invar alloys were designed based on the concept of microalloying.The effects of trace amounts of V and N on microstructure and mechanical properties of hot-rolled invar alloys were studied using Vickers hardness tester,tensile testing machine,electron backscatter diffraction(EBSD)technique,X-ray diffraction(XRD),scanning electron microscopy(SEM)and transmission electron microscopy(TEM),and their action mechanisms were analyzed.The results show that the hot-rolled microstructure of the V-N microalloyed invar alloys is significantly refined,and the hardness and tensile strength are significantly increased.As the N content increases,the grain size is further refined and the distribution is more uniform,resulting in a further increase in tensile strength.A large amount of small and dispersed V(C,N)second phase with a size of about 400 nm is precipitated in the matrix of the V-N microalloyed invar alloys,which pins grain boundaries and dislocations.Fine grain strengthening,precipitation strengthening and dislocation strengthening are the main reasons for the significant improvement in mechanical properties of the V-N microalloyed invar alloys.

关 键 词：因瓦合金 V-N微合金化 细晶强化 析出强化 位错强化 

分 类 号：TG142.3[一般工业技术—材料科学与工程]