The growth behaviour of austenite grain in a V-N microalloyed medium carbon steel and its effect on splitting fracture property were investigated by mechanical tests, fracture morphology and microstructure analysis. W...The growth behaviour of austenite grain in a V-N microalloyed medium carbon steel and its effect on splitting fracture property were investigated by mechanical tests, fracture morphology and microstructure analysis. When the heating temperature is 800℃, the austenite grain size is 7.6 μm, and the fracture surface is uneven with the impact energy of 235.9 J. When the heating temperature increases to 1100 ℃, the austenite grain size grows up to 65.5 μm and the impact fracture surface is much more even with the impact energy of 13.6 J. It is believed that the coarse austenite grain size of 65.5 μm is beneficial for the splitting fracture property of V-N microalloyed medium carbon steel connecting rod. In addition, austenite grain sizes of V-N microalloyed medium carbon steel increase with the increasing in heating tem-perature and holding time. Then, a grain growth model is established to predict austenite grain growth behaviour.展开更多
Single compression tests were carried out with a Gleeble-3800 thermal simulator to investigate hot deform- ation behavior of two vanadium-microalloyed medium-carbon steels for fracture splitting connecting rod. The te...Single compression tests were carried out with a Gleeble-3800 thermal simulator to investigate hot deform- ation behavior of two vanadium-microalloyed medium-carbon steels for fracture splitting connecting rod. The tests were performed to a total true strain of 0.92 at true strain rates ranging from 10-2 to 10 s-1 and deformation temper- ature of 900--1 150 ℃, The results show that hot deformation behavior of the tested steels is similar to that of con- ventional medium-carbon microalloyed steels and dynamic recrystallization is easier to occur at higher deformation temperature and lower strain rate. The austenite deformation resistance and activation energy of deformation increase with increasing vanadium content from 0.15% to 0. 28% and thus the starting time of dynamic recrystallization was delayed. Finer recrystallized austenite grain could he obtained at higher strain rate, lower deformation temperature and higher vanadium content. TEM observation of the specimens quenched just before and after deformation reveals that vanadium is mainly in dissolved solute condition in austenite and thus affects the dynamic recrystallization behavior of the tested steels mainly through solute-drag effect.展开更多
文摘The growth behaviour of austenite grain in a V-N microalloyed medium carbon steel and its effect on splitting fracture property were investigated by mechanical tests, fracture morphology and microstructure analysis. When the heating temperature is 800℃, the austenite grain size is 7.6 μm, and the fracture surface is uneven with the impact energy of 235.9 J. When the heating temperature increases to 1100 ℃, the austenite grain size grows up to 65.5 μm and the impact fracture surface is much more even with the impact energy of 13.6 J. It is believed that the coarse austenite grain size of 65.5 μm is beneficial for the splitting fracture property of V-N microalloyed medium carbon steel connecting rod. In addition, austenite grain sizes of V-N microalloyed medium carbon steel increase with the increasing in heating tem-perature and holding time. Then, a grain growth model is established to predict austenite grain growth behaviour.
基金Item Sponsored by National High Technology Research and Development Program of China(2013AA031605)
文摘Single compression tests were carried out with a Gleeble-3800 thermal simulator to investigate hot deform- ation behavior of two vanadium-microalloyed medium-carbon steels for fracture splitting connecting rod. The tests were performed to a total true strain of 0.92 at true strain rates ranging from 10-2 to 10 s-1 and deformation temper- ature of 900--1 150 ℃, The results show that hot deformation behavior of the tested steels is similar to that of con- ventional medium-carbon microalloyed steels and dynamic recrystallization is easier to occur at higher deformation temperature and lower strain rate. The austenite deformation resistance and activation energy of deformation increase with increasing vanadium content from 0.15% to 0. 28% and thus the starting time of dynamic recrystallization was delayed. Finer recrystallized austenite grain could he obtained at higher strain rate, lower deformation temperature and higher vanadium content. TEM observation of the specimens quenched just before and after deformation reveals that vanadium is mainly in dissolved solute condition in austenite and thus affects the dynamic recrystallization behavior of the tested steels mainly through solute-drag effect.
