摘要
针对HRB400E在冷弯过程中出现断裂现象,分析其断裂原因,并探究其内部缺陷对大规格钢筋冷弯性能的影响。通过热酸低倍确定内部缺陷的存在、光学显微镜(OM)观察试样显微组织组成、扫描电镜-能谱仪(SEM-EDS)观察断口形貌和夹杂物类型、万能力学性能试验机试样进行拉伸性能的测定、维氏硬度计测量硬度。试验结果显示内部裂纹、组织不均匀和夹杂物是HRB400E冷弯断裂的主要原因。它们降低了HRB400E的韧性,破坏了基体的稳定性和连续性,且内部裂纹进一步降低了大规格钢筋屈服和抗拉强度。
In view of the fracture phenomenon of steel HRB400E in the cold bending process,the cause of the fracture was analyzed,and the influence of its internal defects on the performance of large-diameter steel bars was explored,and the existence of internal defects was mainly determined by low thermal acid magnification,the microstructure composition of the sample was observed by optical microscope(OM),the fracture morphology and inclusion type were observed by scanning electron microscope-energy dispersive spectrometer(SEM-EDS),the tensile properties of the samples at the defects and without defects were determined by the universal physical performance testing machine,and the hardness was measured by the Vickers hardness tester.The test results show that there are obvious internal cracks in the HRB400E of cold-formed fractures,and there are elemental segregation and inclusions in the cracks,which mainly come from the cracks caused by the internal defects of the billets,and the existence of internal cracks destroys the overall continuity of the steel bars,which in turn leads to fractures,and the microstructure distribution of the cold-formed fracture specimens is extremely uneven,the grain size of the edge structure is small and the ferrite is more,the grain size of the core structure is larger and the pearlite content is more,and there is an obvious difference with the casting structure,the fracture is a brittle fracture,the tensile performance meets the national standard,and the existence of internal defects leads to the reduction of tensile properties.The test results show that internal cracks,coarse microstructure and inclusions are the main causes of cold-bending fracture in HRB400E,which reduce the toughness of the HRB400E and destroy the stability and continuity of the matrix,and the internal defects further reduce the mechanical properties of the largediameter steel bars.
作者
梁伟佳
张晗
郝飞翔
刘凯
郭福建
李秀程
夏佃秀
成嘉
LIANG Wei-jia;ZHANG Han;HAO Fei-xiang;LIU-Kai;GUO Fu-jian;LI Xiu-cheng;XIA Dian-xiu;SHANG Cheng-jia(Yang Chun New Iron and Steel Co.,Yangchun,Guangdong,529600,P.R.China;Yang Jiang Advanced Alloys Laboratory,Yangjiang,Guangdong,529500,P.R.China;School of Materials Science and Engineering,Guangdong Ocean University,Yangjiang,Guangdong,529599,P.R.China;School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing,100083,P.R.China;School of Mechanical Engineering,University of Jinan,Jinan,Shandong,250022,P.R.China)
出处
《南方金属》
2025年第1期9-14,共6页
Southern Metals
基金
基于大数据技术的高端线棒材产品质量提升研究项目资助(SDZX2021007)。
关键词
HRB400E
冷弯断裂
内部裂纹
显微组织
夹杂物
HRB400E
cold bending fracture
Internal cracks
metallographic structure
inclusion
