Dynamic deformation response of G33 steel under high temperature
The high temperature deformation and fracture behavior of ultra-high strength G33 steel under high strain rate compression are investigated by means of a split Hopkinson pressure bar.Impact tests are performed at strain rates of 1000/s and 2200/s and at temperatures ranging from 25℃ to 700℃.The SEM and TEM techniques are also used to analyze the microstructure evolution of the adiabatic shear band (ASB) and fracture characteristics of the deformed specimens at high temperature.The experimental results indicate that the flow stress of G33 steel is significantly dependent on temperatures and strain rates.The flow stress of G33 steel increases with the increase of strain rates, but decreases with the increase of temperatures.The strain rate sensitivity is more pronounced at the low temperature of 25℃.In addition, G33 steel is more liable to fracture at high temperatures than at 25℃.Observations of microstructure show two well-developed symmetric parabolic adiabatic shear bands on the longitudinal cross-section of the cylindrical specimen deformed at the temperature of 700℃ and at the strain rate of 2200/s.Within the ASB, the width of the fine equiaxed grain structure is about 7μm.The size of those equiaxed grains is approximately 100nm.The fracture analysis results indicate that the ASBs are the predominant deformation and the specimens fracture along adiabatic shear bands.The fracture surfaces of the deformed G33 steel specimens are characterized by two alternating zones: rough dimple zone and relatively smooth shear zone.Further observations reveal that smooth shear zones consist of severely sheared dimples.
Dynamic deformation High temperature Microstructure evolution ASB Fracture characteristics
Youjing Zhang Hongnian Cai Xingwang Cheng Shuangzan Zhao
National Key Laboratory of Science and Technology on Materials under Shock and Impact, School of Material and Engineering, Beijing Institute of Technology, Beijing 100081, Peoples Republic of China
国际会议
北京
英文
89-98
2014-10-19（万方平台首次上网日期，不代表论文的发表时间）