| 摘要: |
| 采用金相显微镜（MM）、扫描电镜（SEM）、透射电镜（TEM）、万能拉伸试验机等对高强度钢筋的显微组织、第二相、断口和力学性能进行表征和试验.结果表明：3种试验钢筋的显微组织均为铁素体+珠光体，其中3#试验钢筋中还含有少量贝氏体；3#试验钢筋中主要析出物为铌钒复合碳氮化物（（Nb，V） （C，N）），呈圆形状，平均粒径为10 nm，在铁素体晶界和珠光体片层间析出；3种试验钢筋的拉伸断口均为韧性断裂，断口上分布着等轴韧窝；随着Nb含量的增加，试验钢筋的抗拉强度和屈服强度增加，但其断后伸长率有所降低；3#试验钢筋的抗拉强度和屈服强度最大，分别为795、525 MPa，断后伸长率较1#和2#试验钢筋小，为21.6%. |
| 关键词: 高强度钢筋 (Nb,V) (C,N) 韧性断裂 韧窝 力学性能 |
| DOI：10.3969/j.issn.1007-9629.2022.08.014 |
| 分类号:TG142.1 |
| 基金项目:国家自然科学基金资助项目（52074095，51864013）；贵州省省级科技计划项目（黔科合支撑［2022］一般053） |
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| Effect of Nb/V Composite Strengthening on Microstructure and Properties of High-Strength Rebars |
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ZENG Zeyun1,2, LI Changrong1,2, LI Zhiying1,2, ZHAI Yongqiang3, WANG Jie3
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1.College of Materials and Metallurgy， Guizhou University， Guiyang 550025， China;2.Guizhou Province Key Laboratory of Metallurgical Engineering and Process Energy Conservation， Guizhou University ， Guiyang 550025， China;3.Shougang Shuicheng Iron and Steel （Group） Co.， Ltd.， Liupanshui 553000， China
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| Abstract: |
| The microstructure， second phase， fracture morphology， mechanical properties of high-strength rebars were characterized by metallographic microscope（MM）， scanning electron microscope （SEM）， transmission electron microscopy（TEM） and universal tensile testing machine. The results show that the microstructure of 1#-3# experimental steel rebars are ferrite + pearlite， and the 3# experimental steel rebar contains a small amount of bainite；the main precipitate of 3# rebar experimental steel is niobium vanadium composite carbonitride （（Nb，V） （C，N））， which is round in shape and precipitate on ferrite grain boundary and pearlite lamellar， with the average particle size of 10 nm；the tensile fracture of 1#-3# experimental steel rebars belong to ductile fracture， and the equiaxed dimples are distributed on the fracture；with the increase of Nb content， the tensile strength and yield strength of experimental steel rebar increase，the elongation after fracture decrease；the tensile strength and yield strength of 3# experimental steel rebar is the largest，reach 795，525 MPa，respectively，the elongation after fracture is 21.6%. |
| Key words: high-strength rebar （Nb,V） （C,N） ductile fracture dimple mechanical property |
